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25
omr-ws-ca73e7f00f5da0443dfdfe35ae59f668c77b991ca9741dabcac6a360687c6665
Two players $A$ and $B$ and another 2001 people form a circle, such that $A$ and $B$ are not in consecutive positions. $A$ and $B$ play in alternating turns, starting with $A$. A play consists of touching one of the people neighboring you, which such person once touched leaves the circle. The winner is the last man sta...
[ "1000" ]
[ "Two players $A$ and $B$ and another 2001 people form a circle, such that $A$ and $B$ are not in consecutive positions. $A$ and $B$ play in alternating turns, starting with $A$. A play consists of touching one of the people neighboring you, which such person once touched leaves the circle. The winner is the last ma...
[ "aops_c6_high_school_olympiads" ]
[ "cot" ]
{ "cot": 3 }
3
0
0
omr-ws-0f9aeef11e1df7492448c83d0596ee2c8a9a19af459b1a34a90d4f8bf9096645
Two players $A$ and $B$ are playing a game with an $m \times n$ chocolate bar divided into a grid of $1 \times 1$ squares. They take turns cutting the chocolate along the grid lines. The player who makes the last cut wins. Determine if there is a winning strategy for either player.
[ "Yes, there is a winning strategy for either player depending on the dimensions \\( m \\) and \\( n \\)." ]
[ "Two players $A$ and $B$ are playing a game with an $m \\times n$ chocolate bar divided into a grid of $1 \\times 1$ squares. They take turns cutting the chocolate along the grid lines. The player who makes the last cut wins. Determine if there is a winning strategy for either player." ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect", "tir" ]
{ "cot": 6, "genselect": 2, "tir": 9 }
17
0
0
omr-ws-aa04105de710639f3d6e89dd3403881a8ff27e8a121dfb359f537c97ac7c750d
Two players $A$ and $B$ are playing a game. $B$ has $p$ sheets of paper lying next to each other on a table. On each of the sheets, he writes some of the numbers from $1$ to $n$ (he can write no number, or all the numbers). On the back of each sheet, he writes all those integers from $1$ to $n$ that he did not write in...
[ "\\( \\left\\lfloor \\log_2(n+1) \\right\\rfloor \\)" ]
[ "Two players $A$ and $B$ are playing a game. $B$ has $p$ sheets of paper lying next to each other on a table. On each of the sheets, he writes some of the numbers from $1$ to $n$ (he can write no number, or all the numbers). On the back of each sheet, he writes all those integers from $1$ to $n$ that he did not wri...
[ "aops_c6_high_school_olympiads" ]
[ "additional_problems" ]
{ "additional_problems": 1 }
1
0
0
omr-ws-811d308088b4880249b19aa4e6f13ff819104458257110509917922d8461459e
Two players $A$ and $B$ have one stone each on a $100 \times 100$ chessboard. They move their stones one after the other, and a move means moving one's stone to a neighboring field (horizontally or vertically, not diagonally). At the beginning of the game, the stone of $A$ lies in the lower left corner, and the one of ...
[ "198" ]
[ "Two players $A$ and $B$ have one stone each on a $100 \\times 100$ chessboard. They move their stones one after the other, and a move means moving one's stone to a neighboring field (horizontally or vertically, not diagonally). At the beginning of the game, the stone of $A$ lies in the lower left corner, and the o...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 3, "genselect": 4 }
7
0
0
omr-ws-caa17373c15808b176657e60035f1ab183f9ebf7a8dcb192126c4000c5f90109
Two players $A$ and $B$ participate in a game where they take turns removing stones from a pile. Initially, there are 2003 stones. On each turn, a player must remove a number of stones that is a divisor of the current number of stones in the pile. The player who removes the last stone loses. Determine the number of sto...
[ "1" ]
[ "Two players $A$ and $B$ participate in a game where they take turns removing stones from a pile. Initially, there are 2003 stones. On each turn, a player must remove a number of stones that is a divisor of the current number of stones in the pile. The player who removes the last stone loses. Determine the number o...
[ "aops_c6_high_school_olympiads" ]
[ "additional_problems" ]
{ "additional_problems": 1 }
1
0
0
omr-ws-efab00f810d9e9e2328aab57ed13c9bd66c009a61c172a4df44f26780dcc8c95
Two players $A$ and $B$ play a game on a $1 \times 2017$ table. On each turn, a player writes either $+1$ or $-1$ in an empty cell. If a player writes a number in a cell where the adjacent cell has the opposite number, that player loses. Player $A$ starts the game. Determine which player has the winning strategy.
[ "Player $A$ has the winning strategy." ]
[ "Two players $A$ and $B$ play a game on a $1 \\times 2017$ table. On each turn, a player writes either $+1$ or $-1$ in an empty cell. If a player writes a number in a cell where the adjacent cell has the opposite number, that player loses. Player $A$ starts the game. Determine which player has the winning strategy....
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect", "tir" ]
{ "cot": 15, "genselect": 7, "tir": 10 }
32
0
0
omr-ws-6d18ee7935d067e109f89b5497848d33085c6684f2078fbc2a0235597b644ded
Two players $A$ and $B$ play a game on a $1 \times m$ board using $2012$ pieces numbered from $1$ to $2012$. At each turn, $A$ chooses a piece and $B$ places it in an empty spot. After $k$ turns, if all pieces are placed on the board in increasing order, then $B$ wins; otherwise, $A$ wins. For which values of $(m, k)$ ...
[ "$m \\ge 2012$ or $m < 2012$ and $k < \\log_2(m+2)$" ]
[ "Two players $A$ and $B$ play a game on a $1 \\times m$ board using $2012$ pieces numbered from $1$ to $2012$. At each turn, $A$ chooses a piece and $B$ places it in an empty spot. After $k$ turns, if all pieces are placed on the board in increasing order, then $B$ wins; otherwise, $A$ wins. For which values of $(m...
[ "aops_c6_high_school_olympiads" ]
[ "additional_problems" ]
{ "additional_problems": 1 }
1
0
0
omr-ws-e06354fa3aa6307e8915c6267dc724347186b885771bda2cbe03ba4aa82f32ba
Two players $A$ and $B$ play a game on a circle with $2n$ cells. $A$ begins and each player alternates turns by choosing a free cell and writing either $O$ or $M$ in it. The player who first creates the sequence $OMO$ in three successive cells wins the game. If no such sequence is formed, the game is a draw. Assuming p...
[ "2n" ]
[ "Two players $A$ and $B$ play a game on a circle with $2n$ cells. $A$ begins and each player alternates turns by choosing a free cell and writing either $O$ or $M$ in it. The player who first creates the sequence $OMO$ in three successive cells wins the game. If no such sequence is formed, the game is a draw. Assum...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 4, "genselect": 3 }
7
0
0
omr-ws-825d68da3583efde80c8ad66cc02708560986e8b1480ab8e26ca8454c3b86e67
Two players $A$ and $B$ play a game on an infinite grid of regular hexagons. Initially, all the grid cells are empty. In each turn, $A$ places a counter in two adjacent empty hexagons, and $B$ removes any one counter. Define $f(k)$ as the minimum number of turns required for $A$ to ensure that there are $k$ consecutive...
[ "0" ]
[ "Two players $A$ and $B$ play a game on an infinite grid of regular hexagons. Initially, all the grid cells are empty. In each turn, $A$ places a counter in two adjacent empty hexagons, and $B$ removes any one counter. Define $f(k)$ as the minimum number of turns required for $A$ to ensure that there are $k$ consec...
[ "aops_c5_contests_amp_programs" ]
[ "cot", "genselect" ]
{ "cot": 2, "genselect": 2 }
4
0
0
omr-ws-bd05bc156b5417d52c839069882253d454f8e0750582322b702931dfc7737c48
Two players $A$ and $B$ play a game where $A$ chooses a point with integer coordinates and colors it green, and $B$ then chooses 10 uncolored points and colors them yellow. The game continues with the same rules. The goal of $A$ is to achieve $111^2$ green points that are the intersections of $111$ horizontal lines and...
[ "A" ]
[ "Two players $A$ and $B$ play a game where $A$ chooses a point with integer coordinates and colors it green, and $B$ then chooses 10 uncolored points and colors them yellow. The game continues with the same rules. The goal of $A$ is to achieve $111^2$ green points that are the intersections of $111$ horizontal line...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 12, "genselect": 6 }
18
0
0
omr-ws-6dc519dff6da34a31bb30921db69b40276c9dc087959430785e4a3f24fce25ab
Two players $A$ and $B$ play a game where $B$ places a stone within a distance of $\leq 2001$ from $A$'s initial position. Player $A$ can see the stone only if within a distance of $\leq 1$ and can move in steps of size $\leq 1$. After each step, $A$ can ask if they are "near" or "far" from the stone, with $B$ respondi...
[ "no_valid_answer_found" ]
[ "Two players $A$ and $B$ play a game where $B$ places a stone within a distance of $\\leq 2001$ from $A$'s initial position. Player $A$ can see the stone only if within a distance of $\\leq 1$ and can move in steps of size $\\leq 1$. After each step, $A$ can ask if they are \"near\" or \"far\" from the stone, with ...
[ "aops_c6_high_school_olympiads" ]
[ "additional_problems" ]
{ "additional_problems": 1 }
1
0
0
omr-ws-ac050dc87c32f4568facffb4cebf3142b48b514d500549a147a0b77945e5286a
Two players $A$ and $B$ play a game where they take turns writing one digit on the blackboard, either to the right or left of the existing sequence. $A$ starts with an empty blackboard. $B$ wins if, after any of $B$'s moves, the sequence of digits forms a perfect square. If $A$ follows an optimal strategy, what is the ...
[ "3" ]
[ "Two players $A$ and $B$ play a game where they take turns writing one digit on the blackboard, either to the right or left of the existing sequence. $A$ starts with an empty blackboard. $B$ wins if, after any of $B$'s moves, the sequence of digits forms a perfect square. If $A$ follows an optimal strategy, what is...
[ "aops_c6_high_school_olympiads" ]
[ "additional_problems" ]
{ "additional_problems": 1 }
1
0
0
omr-ws-ba164015a250d44b8a2cdec80cf3e15ae0435764518d09cc7afb4cf084ce9c21
Two players $A$ and $B$ play a game with a ball and $n$ boxes placed onto the vertices of a regular $n$-gon where $n$ is a positive integer. Initially, the ball is hidden in a box by player $A$. At each step, $B$ chooses a box, then player $A$ says the distance of the ball to the selected box to player $B$ and moves th...
[ "n-1" ]
[ "Two players $A$ and $B$ play a game with a ball and $n$ boxes placed onto the vertices of a regular $n$-gon where $n$ is a positive integer. Initially, the ball is hidden in a box by player $A$. At each step, $B$ chooses a box, then player $A$ says the distance of the ball to the selected box to player $B$ and mov...
[ "aops_c6_high_school_olympiads" ]
[ "cot" ]
{ "cot": 10 }
10
0
0
omr-ws-8dede4444b4aa717e42f73da253dfda1390db6ce9a5c5a113f912a428ba6692a
Two players $A$ and $B$ play a game with a calculator. The calculator has digits (excluding 0) arranged in a grid. Player $A$ starts by pressing a digit and then pressing the "+" button. Player $B$ then presses a digit in the same row or column as the one pressed by $A$, but not the same digit, and also presses "+." Th...
[ "Player $A$ has a winning strategy." ]
[ "Two players $A$ and $B$ play a game with a calculator. The calculator has digits (excluding 0) arranged in a grid. Player $A$ starts by pressing a digit and then pressing the \"+\" button. Player $B$ then presses a digit in the same row or column as the one pressed by $A$, but not the same digit, and also presses ...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "tir" ]
{ "cot": 3, "tir": 20 }
23
0
0
omr-ws-4c28ccf0209531eb902b66a2c384e44a1febb0434a50f19820cad906e08e417c
Two players $A$ and $B$ play a game with two fair six-sided dice. Player $A$ can choose to either roll one die and double the result or roll both dice and take the sum of the results to get $a$. Player $B$ always rolls both dice and takes the sum of the results to get $b$. If $a=b$, the process is repeated; otherwise, ...
[ "Roll both dice and take the sum of the results." ]
[ "Two players $A$ and $B$ play a game with two fair six-sided dice. Player $A$ can choose to either roll one die and double the result or roll both dice and take the sum of the results to get $a$. Player $B$ always rolls both dice and takes the sum of the results to get $b$. If $a=b$, the process is repeated; otherw...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect", "tir" ]
{ "cot": 10, "genselect": 6, "tir": 3 }
19
0
0
omr-ws-bbbb172036d503d492ec292b7fd815a1fcee297813d67bb251ac9919f3145306
Two players $A$ and $B$ play a game. $A$ writes two different numbers between $1$ and $100$ on two sheets, puts them into two envelopes, and hands them to $B$. $B$ opens one of the envelopes randomly and must guess whether the opened number is larger than the other number. If $B$ uses an optimal strategy, what is the p...
[ "\\dfrac{50}{99}" ]
[ "Two players $A$ and $B$ play a game. $A$ writes two different numbers between $1$ and $100$ on two sheets, puts them into two envelopes, and hands them to $B$. $B$ opens one of the envelopes randomly and must guess whether the opened number is larger than the other number. If $B$ uses an optimal strategy, what is ...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 4, "genselect": 4 }
8
0
0
omr-ws-dfd4a1f516e79f1ba0f2168052be1e0474b8f27604c2e66ccc692f9a0042c845
Two players $A$ and $B$ play alternately with respective probabilities of winning each move $a$ and $b$. The game stops when one of the players wins for the first time. Assuming that $A$ goes first, find a relationship between $a$ and $b$ such that the game is fair.
[ "\\( a = \\frac{b}{b+1} \\)" ]
[ "Two players $A$ and $B$ play alternately with respective probabilities of winning each move $a$ and $b$. The game stops when one of the players wins for the first time. Assuming that $A$ goes first, find a relationship between $a$ and $b$ such that the game is fair." ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "tir" ]
{ "cot": 16, "tir": 17 }
33
0
0
omr-ws-70326685dcbd76e2b9571d1383accf6440063d109bc2edf051ab3e47ea9e3231
Two players $A$ and $B$ play alternatively in a convex polygon with $n \geq 5$ sides. In each turn, the corresponding player has to draw a diagonal that does not intersect any previously drawn diagonals. A player loses if after their turn, a quadrilateral is formed such that its two diagonals are not drawn. $A$ starts ...
[ "B" ]
[ "Two players $A$ and $B$ play alternatively in a convex polygon with $n \\geq 5$ sides. In each turn, the corresponding player has to draw a diagonal that does not intersect any previously drawn diagonals. A player loses if after their turn, a quadrilateral is formed such that its two diagonals are not drawn. $A$ s...
[ "aops_c6_high_school_olympiads" ]
[ "cot" ]
{ "cot": 8 }
8
0
0
omr-ws-2b47aa7416f491b3031dd8fde02c466cd24e8488e974e1b5d678cfab08a71e1d
Two players $A$ and $B$ play on a $2N \times 2N$ square. In turn ($A$ starts), they draw a $2 \times 1$ block on the square. Blocks must be placed horizontally or vertically and cannot overlap. Whoever leaves the opponent with no lawful moves wins. Who wins, and what is the winning strategy?
[ "B wins with the strategy of mirroring A's moves with respect to the center of the square." ]
[ "Two players $A$ and $B$ play on a $2N \\times 2N$ square. In turn ($A$ starts), they draw a $2 \\times 1$ block on the square. Blocks must be placed horizontally or vertically and cannot overlap. Whoever leaves the opponent with no lawful moves wins. Who wins, and what is the winning strategy?" ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "tir" ]
{ "cot": 16, "tir": 19 }
35
0
0
omr-ws-3e701b83317e18f2eb8b85a37b34958970ea9ccee8d5422b0a62b43ac902e812
Two players $A$ and $B$ play the following game. Before the game starts, $A$ chooses 1000 not necessarily different odd primes, and then $B$ chooses half of them and writes them on a blackboard. In each turn, a player chooses a positive integer $n$, erases some primes $p_1, p_2, \dots, p_n$ from the blackboard, and wri...
[ "1" ]
[ "Two players $A$ and $B$ play the following game. Before the game starts, $A$ chooses 1000 not necessarily different odd primes, and then $B$ chooses half of them and writes them on a blackboard. In each turn, a player chooses a positive integer $n$, erases some primes $p_1, p_2, \\dots, p_n$ from the blackboard, a...
[ "aops_c6_high_school_olympiads" ]
[ "cot" ]
{ "cot": 3 }
3
0
0
omr-ws-c006b621d24a534f847fada5e390ab0c9e07da3efe3e186f154b22038a3fff17
Two players $A$ and $B$ take turns playing a game with a pile of $2003$ stones. In his first turn, $A$ selects a divisor of $2003$ and removes that number of stones from the pile. $B$ then chooses a divisor of the number of remaining stones and removes that number of stones, and so on. The player who has to remove the ...
[ "1" ]
[ "Two players $A$ and $B$ take turns playing a game with a pile of $2003$ stones. In his first turn, $A$ selects a divisor of $2003$ and removes that number of stones from the pile. $B$ then chooses a divisor of the number of remaining stones and removes that number of stones, and so on. The player who has to remove...
[ "aops_c6_high_school_olympiads" ]
[ "cot" ]
{ "cot": 7 }
7
0
0
omr-ws-b22cb2ce97ed4271b7d848835e2dcf4a8d1f360b410140ede45920a2e2a14a89
Two players $A$ and $B$ take turns taking stones from a pile of $N$ stones. Player $A$ starts. On each turn, $B$ can take 1, 2, or 3 stones, while $A$ can take 2, 3, or 4 stones, or 1 stone if it is the last one in the pile. The player who takes the last stone loses. Determine for what values of $N$ player $A$ has a wi...
[ "A \\text{ wins if } N \\not\\equiv 1, 2 \\pmod{5}; B \\text{ wins otherwise}" ]
[ "Two players $A$ and $B$ take turns taking stones from a pile of $N$ stones. Player $A$ starts. On each turn, $B$ can take 1, 2, or 3 stones, while $A$ can take 2, 3, or 4 stones, or 1 stone if it is the last one in the pile. The player who takes the last stone loses. Determine for what values of $N$ player $A$ has...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 14, "genselect": 7 }
21
0
0
omr-ws-a62657df8dd55d412a4c366cae2cc98114f7f0d4a8cf1a30dfd6a26dcf60976f
Two players (A and B) play a game with 2n cards, each with a positive integer written on it. The cards are shuffled and laid out in a row. A starts and the players take turns to remove one card from either end of the row, until B picks up the remaining card. Each player's score is the sum of the numbers on their chosen...
[ "n(n+1)" ]
[ "Two players (A and B) play a game with 2n cards, each with a positive integer written on it. The cards are shuffled and laid out in a row. A starts and the players take turns to remove one card from either end of the row, until B picks up the remaining card. Each player's score is the sum of the numbers on their c...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 4, "genselect": 5 }
9
0
0
omr-ws-c2bff5dd4d6a3f4242a2098b550f53ec6b9f5b5c7a603573a6ee29f88dbc1282
Two players (Kate and Adam) play a variant of Nim with 11 sticks. Each player can remove either one or any prime number of sticks. The player who is forced to take the last stick loses. If Kate plays perfectly, she will always win. Give the sum of all the starting moves that lead to a sure win for Kate.
[ "2" ]
[ "Two players (Kate and Adam) play a variant of Nim with 11 sticks. Each player can remove either one or any prime number of sticks. The player who is forced to take the last stick loses. If Kate plays perfectly, she will always win. Give the sum of all the starting moves that lead to a sure win for Kate." ]
[ "aops_c4_high_school_math" ]
[ "cot", "genselect" ]
{ "cot": 13, "genselect": 4 }
17
0
0
omr-ws-50d2fb5efaa46d2bd86c41d830b4a2cae284e70fb3e741084c774c54f968ac38
Two players A and B alternately remove stones from two piles, one with 100 stones and one with 252 stones. On each turn, a player can remove a number of stones from one pile, which is a divisor of the number of stones in the other pile. The player who makes the last move wins. Determine which player can always guarante...
[ "A" ]
[ "Two players A and B alternately remove stones from two piles, one with 100 stones and one with 252 stones. On each turn, a player can remove a number of stones from one pile, which is a divisor of the number of stones in the other pile. The player who makes the last move wins. Determine which player can always gua...
[ "aops_c4_high_school_math", "c4_high_school_math" ]
[ "cot", "genselect", "tir" ]
{ "cot": 3, "genselect": 1, "tir": 18 }
22
0
0
omr-ws-ed6e3c8ee70e91219dad63af52456b81dbe555d1104d012cd5f5d3b3a6d05661
Two players A and B alternately take chips from two piles with $a$ and $b$ chips, respectively, where initially $a > b$. A move consists of taking a multiple of the other pile from a pile. The winner is the one who takes the last chip in one of the piles. For what value of $\alpha$ can player A force a win if initially...
[ "\\( \\alpha = \\frac{\\sqrt{5} + 1}{2} \\)" ]
[ "Two players A and B alternately take chips from two piles with $a$ and $b$ chips, respectively, where initially $a > b$. A move consists of taking a multiple of the other pile from a pile. The winner is the one who takes the last chip in one of the piles. For what value of $\\alpha$ can player A force a win if ini...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "tir" ]
{ "cot": 16, "tir": 23 }
39
0
0
omr-ws-e1188fb1f5857969775887cad722057cd049ab833a0f6a9b669290ff0d45ace2
Two players A and B are playing a championship series where the winner is the first to win at least 6 games and be ahead by 2 games. The probability of A winning a match is 2/3 and the probability of B winning a match is 1/3. Given that B has won the first four games, find the probability that A wins the championship.
[ "\\( \\frac{1088}{3645} \\)" ]
[ "Two players A and B are playing a championship series where the winner is the first to win at least 6 games and be ahead by 2 games. The probability of A winning a match is 2/3 and the probability of B winning a match is 1/3. Given that B has won the first four games, find the probability that A wins the champions...
[ "aops_c4_high_school_math" ]
[ "cot", "tir" ]
{ "cot": 15, "tir": 11 }
26
0
0
omr-ws-00f08ab0420c0231a52a41b9fed85da8e1ff68d2d6789f75ae961d9a957f784d
Two players A and B play a game consecutively until one loses all their capital. Player A starts with \$a and player B with \$b. The probability of A winning each game is \( p \) and the probability of B winning each game is \( q = 1 - p \). Find the probability of ruin for each player if no limit is set for the number...
[ " \\frac{a}{a + b} " ]
[ "Two players A and B play a game consecutively until one loses all their capital. Player A starts with \\$a and player B with \\$b. The probability of A winning each game is \\( p \\) and the probability of B winning each game is \\( q = 1 - p \\). Find the probability of ruin for each player if no limit is set for...
[ "aops_c7_college_math" ]
[ "cot" ]
{ "cot": 10 }
10
0
0
omr-ws-7b89d8d8131476634652f1656c42a3412b26b532bf66db2a480348d0cc24c2db
Two players A and B play a game of dice. They roll a pair of dice alternately. The player who gets the event (1,1) first wins. If A starts, what is the probability that A wins the game?
[ "\\(\\frac{36}{71}\\)" ]
[ "Two players A and B play a game of dice. They roll a pair of dice alternately. The player who gets the event (1,1) first wins. If A starts, what is the probability that A wins the game?" ]
[ "aops_c4_high_school_math" ]
[ "cot", "tir" ]
{ "cot": 15, "tir": 30 }
45
0
0
omr-ws-04fe57acbd57bedb2db038a63a6511ad76c9c99f1df92c167bdac24d8412a88c
Two players A and B play a game starting with a pile of 1000 stones. Player A first removes any number \( s \) of stones such that \( 0 < s < 1000 \). Thereafter, each player can remove any positive integer number of stones that is a divisor of the number taken in the preceding move. The player who makes the last move ...
[ "Player A can always guarantee victory." ]
[ "Two players A and B play a game starting with a pile of 1000 stones. Player A first removes any number \\( s \\) of stones such that \\( 0 < s < 1000 \\). Thereafter, each player can remove any positive integer number of stones that is a divisor of the number taken in the preceding move. The player who makes the l...
[ "aops_c4_high_school_math" ]
[ "cot", "tir" ]
{ "cot": 3, "tir": 12 }
15
0
0
omr-ws-e390ae19c2cf6917b8f06447701427f309b4288add8d4fd976af8d5b9bf2ccd2
Two players A and B play a game where initially, there are $m$ equal positive integers $n$ written on a blackboard. A begins and the players move alternately. The player to move chooses one of the non-zero numbers on the board. If this number $k$ is the smallest among all positive integers on the board, the player repl...
[ "- If \\( m \\) is even, B wins.\n- If \\( m \\) is odd and \\( n \\) is odd, A wins.\n- If \\( m \\) is odd and \\( n \\) is even, B wins." ]
[ "Two players A and B play a game where initially, there are $m$ equal positive integers $n$ written on a blackboard. A begins and the players move alternately. The player to move chooses one of the non-zero numbers on the board. If this number $k$ is the smallest among all positive integers on the board, the player...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "tir" ]
{ "cot": 1, "tir": 18 }
19
0
0
omr-ws-0730b689af8935b4da36ba0ef79536096f76dbf20555418c7119efc33b8f5f69
Two players A and B play a game with a calculator where the figures (except 0) are arranged in a specific table, and the ‘+’ key is also included. Player A starts by pressing a figure and then pressing the + key. Player B then presses a figure in the same row or column as the one pressed by A, but not the same figure, ...
[ "B" ]
[ "Two players A and B play a game with a calculator where the figures (except 0) are arranged in a specific table, and the ‘+’ key is also included. Player A starts by pressing a figure and then pressing the + key. Player B then presses a figure in the same row or column as the one pressed by A, but not the same fig...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 14, "genselect": 2 }
16
0
0
omr-ws-cec78ea320440264957efc4ac8f109a7715d222c3b5a47b4fa663a8be8842c56
Two players A and B play a series of "2n" games. Each game can result in either a win or a loss for A. Find the total number of ways in which A can win the series of these games.
[ "\\(2^{2n-1} - \\frac{1}{2}\\binom{2n}{n}\\)" ]
[ "Two players A and B play a series of \"2n\" games. Each game can result in either a win or a loss for A. Find the total number of ways in which A can win the series of these games." ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "tir" ]
{ "cot": 16, "tir": 22 }
38
0
0
omr-ws-b519b89b8403f0e6e285ecb703899a53c3f5a64e78c05a5f056176c776076085
Two players A and B play the following game: Suppose on the table is the positive integer \( n \). Player A chooses a positive integer \( x \), and player B will replace \( n \) by either \( n + x \) or \( n - x \) on the table. Find all values of \( k \) such that player A can always ensure that at some point, a power...
[ "\\( k = 2^t + 1 \\) for any non-negative integer \\( t \\)." ]
[ "Two players A and B play the following game: Suppose on the table is the positive integer \\( n \\). Player A chooses a positive integer \\( x \\), and player B will replace \\( n \\) by either \\( n + x \\) or \\( n - x \\) on the table. Find all values of \\( k \\) such that player A can always ensure that at so...
[ "aops_c6_high_school_olympiads" ]
[ "additional_problems" ]
{ "additional_problems": 1 }
1
0
0
omr-ws-ecd26eb6e78affcd629e271f6f2511ad2554eba067110b2bbb084db090494b1c
Two players A and B take turns drawing a line that joins two points among $n = 2016$ points given in a circle. The first player to form a cycle loses. Who has the winning strategy?
[ "A" ]
[ "Two players A and B take turns drawing a line that joins two points among $n = 2016$ points given in a circle. The first player to form a cycle loses. Who has the winning strategy?" ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "tir" ]
{ "cot": 16, "tir": 21 }
37
0
0
omr-ws-e6a866679da6513f428e44c4f4d07c410aeb98dcb60f07b0e1526948b838dd9f
Two players A and B take turns drawing a line that joins two points among $n = 2017$ points given in a circle. The first player to form a cycle loses. Who has the winning strategy?
[ "A" ]
[ "Two players A and B take turns drawing a line that joins two points among $n = 2017$ points given in a circle. The first player to form a cycle loses. Who has the winning strategy?" ]
[ "aops_c6_high_school_olympiads" ]
[ "additional_problems" ]
{ "additional_problems": 1 }
1
0
0
omr-ws-063d5f2283910857e532a30f37b551de0caeddd5a504f41b2466f2b07c9427e6
Two players A and B take turns replacing asterisks in the matrix $\left({\begin{smallmatrix} * & * & * & * \\ * & * & * & * \\ * & * & * & * \\ * & * & * & * \\ \end{smallmatrix}}\right)$ with any numbers. If the resulting matrix is singular, A wins; otherwise, B wins. Who has a winning strategy if A goes first?
[ "B has a winning strategy." ]
[ "Two players A and B take turns replacing asterisks in the matrix $\\left({\\begin{smallmatrix}\n* & * & * & * \\\\\n* & * & * & * \\\\\n* & * & * & * \\\\\n* & * & * & * \\\\\n\\end{smallmatrix}}\\right)$ with any numbers. If the resulting matrix is singular, A wins; otherwise, B wins. Who has a winning strategy i...
[ "aops_c7_college_math" ]
[ "cot", "genselect", "tir" ]
{ "cot": 4, "genselect": 2, "tir": 11 }
17
0
0
omr-ws-52aa2617da0b8e873fafd7293d724ec8ef4752377d22f3fb2e3d742f06e8d4a3
Two players A and B take turns replacing asterisks in the matrix $\left({\begin{smallmatrix} * & * & * & * \\ * & * & * & * \\ * & * & * & * \\ * & * & * & * \\ \end{smallmatrix}}\right)$ with any numbers. If the resulting matrix is singular, A wins; otherwise, B wins. Who has a winning strategy if B goes first?
[ "A has a winning strategy." ]
[ "Two players A and B take turns replacing asterisks in the matrix $\\left({\\begin{smallmatrix}\n* & * & * & * \\\\\n* & * & * & * \\\\\n* & * & * & * \\\\\n* & * & * & * \\\\\n\\end{smallmatrix}}\\right)$ with any numbers. If the resulting matrix is singular, A wins; otherwise, B wins. Who has a winning strategy i...
[ "aops_c7_college_math" ]
[ "cot", "genselect", "tir" ]
{ "cot": 9, "genselect": 7, "tir": 16 }
32
0
0
omr-ws-bcab2f76f01854e692b4b2df727591fc337bba5b2b4408f159b40e20b98ee8fa
Two players A and B take turns replacing asterisks in the matrix $\left({\begin{smallmatrix} * & * & * \\ * & * & * \\ * & * & * \\ \end{smallmatrix}}\right)$ with any numbers. If the resulting matrix is singular, A wins; otherwise, B wins. Who has a winning strategy if A goes first?
[ "A has a winning strategy." ]
[ "Two players A and B take turns replacing asterisks in the matrix $\\left({\\begin{smallmatrix}\n* & * & * \\\\\n* & * & * \\\\\n* & * & * \\\\\n\\end{smallmatrix}}\\right)$ with any numbers. If the resulting matrix is singular, A wins; otherwise, B wins. Who has a winning strategy if A goes first?" ]
[ "aops_c7_college_math" ]
[ "cot", "tir" ]
{ "cot": 16, "tir": 9 }
25
0
0
omr-ws-ba9119e8235afc51683022298567885caff7159614b5297193b640150bf55c20
Two players A and B take turns replacing asterisks in the matrix $\left({\begin{smallmatrix} * & * & * \\ * & * & * \\ * & * & * \\ \end{smallmatrix}}\right)$ with any numbers. If the resulting matrix is singular, A wins; otherwise, B wins. Who has a winning strategy if B goes first?
[ "A has a winning strategy." ]
[ "Two players A and B take turns replacing asterisks in the matrix $\\left({\\begin{smallmatrix}\n* & * & * \\\\\n* & * & * \\\\\n* & * & * \\\\\n\\end{smallmatrix}}\\right)$ with any numbers. If the resulting matrix is singular, A wins; otherwise, B wins. Who has a winning strategy if B goes first?" ]
[ "aops_c7_college_math" ]
[ "tir" ]
{ "tir": 1 }
1
0
0
omr-ws-f48cea6f2a1fd50a506b75dd6c6d013a0b47f59a21f829f82813f429545fde22
Two players \( A \) and \( B \) and another 2001 people form a circle, such that \( A \) and \( B \) are not in consecutive positions. \( A \) and \( B \) play in alternating turns, starting with \( A \). A play consists of touching one of the people neighboring you, which such person once touched leaves the circle. Th...
[ "1000" ]
[ "Two players \\( A \\) and \\( B \\) and another 2001 people form a circle, such that \\( A \\) and \\( B \\) are not in consecutive positions. \\( A \\) and \\( B \\) play in alternating turns, starting with \\( A \\). A play consists of touching one of the people neighboring you, which such person once touched le...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 2, "genselect": 8 }
10
0
0
omr-ws-3a6e56008ffb86ec2a827b6fd980ae01dd0013d31914375d53ccbd5e2478373a
Two players \( A \) and \( B \) play a game on a calculator with digits 1 through 9. \( A \) turns on the calculator and presses a digit, then presses the button "+". \( A \) passes the calculator to \( B \), which presses a digit in the same row or column with the one pressed by \( A \) that is not the same as the las...
[ "\\( A \\) has the winning strategy." ]
[ "Two players \\( A \\) and \\( B \\) play a game on a calculator with digits 1 through 9. \\( A \\) turns on the calculator and presses a digit, then presses the button \"+\". \\( A \\) passes the calculator to \\( B \\), which presses a digit in the same row or column with the one pressed by \\( A \\) that is not ...
[ "aops_c6_high_school_olympiads" ]
[ "tir" ]
{ "tir": 16 }
16
0
0
omr-ws-9b6c44db48b0fe46a9423aee75e0fecc0f0360dc0780da4b3b2ca99852a677c5
Two players \( A \) and \( B \) play a game where they toss a fair coin. If heads appears, \( A \) gets a point; if tails appears, \( B \) gets a point. The game ends when either \( A \) leads by \( a \) points or \( B \) leads by \( b \) points, where \( a \) and \( b \) are positive integers. What is the expected len...
[ "\\( ab \\)" ]
[ "Two players \\( A \\) and \\( B \\) play a game where they toss a fair coin. If heads appears, \\( A \\) gets a point; if tails appears, \\( B \\) gets a point. The game ends when either \\( A \\) leads by \\( a \\) points or \\( B \\) leads by \\( b \\) points, where \\( a \\) and \\( b \\) are positive integers....
[ "aops_c7_college_math" ]
[ "cot", "tir" ]
{ "cot": 16, "tir": 9 }
25
0
0
omr-ws-f081b28e256b7f5680a5a3ac3d1cfb920fe5f8061fd6e738e360f4e86a277229
Two players alternate shooting free throws in basketball. For each attempt, player 1 has a \(1/3\) probability of success and player 2 has a \(1/4\) probability of success. What is the probability that player 1 succeeds before player 2?
[ "\\(\\frac{2}{3}\\)" ]
[ "Two players alternate shooting free throws in basketball. For each attempt, player 1 has a \\(1/3\\) probability of success and player 2 has a \\(1/4\\) probability of success. What is the probability that player 1 succeeds before player 2?" ]
[ "aops_c4_high_school_math" ]
[ "cot", "tir" ]
{ "cot": 15, "tir": 27 }
42
0
0
omr-ws-cd5af0fe8800b47b1bc93c9b41d509a0f207d4c4741fa8f2e051f67c77e044bc
Two players alternate turns changing a number on a blackboard to the difference of that number and one of its divisors. The player who writes zero loses. Starting with the number 2013, which player can guarantee a win?
[ "The first player can guarantee a win." ]
[ "Two players alternate turns changing a number on a blackboard to the difference of that number and one of its divisors. The player who writes zero loses. Starting with the number 2013, which player can guarantee a win?" ]
[ "aops_c6_high_school_olympiads" ]
[ "tir" ]
{ "tir": 1 }
1
0
0
omr-ws-8b0b36a7cc2d9612e936e83452ee1e3419be1d5a72250f1123b413834138f21b
Two players alternate turns counting consecutive numbers. The first player starts from the number $1$. In the following turns, the next player starts counting from the next number. In a turn, a player can count up to $5$ numbers. The objective of the game is to make your opponent speak the number $21$. Problem 3a: Ther...
[ "First player wins." ]
[ "Two players alternate turns counting consecutive numbers. The first player starts from the number $1$. In the following turns, the next player starts counting from the next number. In a turn, a player can count up to $5$ numbers. The objective of the game is to make your opponent speak the number $21$.\n\nProblem ...
[ "aops_c4_high_school_math" ]
[ "cot", "tir" ]
{ "cot": 14, "tir": 3 }
17
0
0
omr-ws-6cc9dd780952eed39134c95de367e5e66383f21a1f0595276f6259d6c13c3acd
Two players alternate writing down integers between $1$ and $1000$ such that no integer which is a divisor of some already written integer is written. Determine who has a winning strategy.
[ "The first player has a winning strategy." ]
[ "Two players alternate writing down integers between $1$ and $1000$ such that no integer which is a divisor of some already written integer is written. Determine who has a winning strategy." ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect", "tir" ]
{ "cot": 13, "genselect": 5, "tir": 10 }
28
0
0
omr-ws-129ea8349608b8021b5ec3c90646f1ccbf20d53acaf8c4b77cab2589e099c18a
Two players alternate writing positive divisors of $328$ on the board, subject to the following rules: - No divisor of a previously written number may be written. - The player who writes $328$ loses. Who has a winning strategy, the first player or the second player?
[ "The first player has a winning strategy." ]
[ "Two players alternate writing positive divisors of $328$ on the board, subject to the following rules:\n- No divisor of a previously written number may be written.\n- The player who writes $328$ loses.\nWho has a winning strategy, the first player or the second player?" ]
[ "aops_c4_high_school_math" ]
[ "cot", "genselect", "tir" ]
{ "cot": 8, "genselect": 4, "tir": 14 }
26
0
0
omr-ws-a5ffec84e64cd6eb9aad8ea10f7a0e019371c002b5e5a47ee8db0f010e369059
Two players alternate writing signs and numbers to the right on a board starting with the number 0. The first player always writes either a $+$ or $-$ sign, while the second player writes one of the numbers $1, 2, \ldots, 1993$, each exactly once. The game ends after 1993 moves. The second player wins a score equal to ...
[ "1993" ]
[ "Two players alternate writing signs and numbers to the right on a board starting with the number 0. The first player always writes either a $+$ or $-$ sign, while the second player writes one of the numbers $1, 2, \\ldots, 1993$, each exactly once. The game ends after 1993 moves. The second player wins a score equ...
[ "aops_c6_high_school_olympiads" ]
[ "additional_problems" ]
{ "additional_problems": 1 }
1
0
0
omr-ws-fd2a5f8635b9ecbcbfbff4f4cdfb5ecfb24570f0ec9a24ddf727f4d3cf915988
Two players alternately choose 10 out of 11 boxes and place one ball in each of the chosen boxes. The player who first gets a box with 21 balls wins. Which player has a winning strategy?
[ "The second player has a winning strategy." ]
[ "Two players alternately choose 10 out of 11 boxes and place one ball in each of the chosen boxes. The player who first gets a box with 21 balls wins. Which player has a winning strategy?" ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect", "tir" ]
{ "cot": 8, "genselect": 4, "tir": 3 }
15
0
0
omr-ws-8578351a0d0e6c70f8d34bdc1513c99679204d1e555281788355bfb609953d37
Two players alternately extract balls (without replacement) from an urn containing $M$ white and $N$ black balls. The winner is the first one to take out a white ball. Find the probability of the first participant winning if $N = 4$ and $M = 1$.
[ "\\(\\frac{3}{5}\\)" ]
[ "Two players alternately extract balls (without replacement) from an urn containing $M$ white and $N$ black balls. The winner is the first one to take out a white ball. Find the probability of the first participant winning if $N = 4$ and $M = 1$." ]
[ "aops_c7_college_math" ]
[ "cot", "tir" ]
{ "cot": 16, "tir": 25 }
41
0
0
omr-ws-a294dc980a700d917f597941880d39670ece62331f7d790f831a674a940aff35
Two players alternately fold an $m \times n$ checkered sheet of paper along the lines of the cells. The one who cannot make another move loses. Who will win if both play optimally: the beginner or his opponent?
[ "\\text{Second player}" ]
[ "Two players alternately fold an $m \\times n$ checkered sheet of paper along the lines of the cells. The one who cannot make another move loses. Who will win if both play optimally: the beginner or his opponent?" ]
[ "aops_c6_high_school_olympiads" ]
[ "cot" ]
{ "cot": 6 }
6
0
0
omr-ws-b7334656863ff87823cc10f53761cb756c28263d4ef6ced908950f5f3943c6c1
Two players alternately replace the stars in the expression \( x^{2000} + x^{1999} + \cdots + x + 1 \) by real numbers. The player who makes the last move loses if the resulting polynomial has a real root \( t \) with \( |t| < 1 \), and wins otherwise. Give a winning strategy for one of the players.
[ "\\text{The second player has a winning strategy.}" ]
[ "Two players alternately replace the stars in the expression \\( x^{2000} + x^{1999} + \\cdots + x + 1 \\) by real numbers. The player who makes the last move loses if the resulting polynomial has a real root \\( t \\) with \\( |t| < 1 \\), and wins otherwise. Give a winning strategy for one of the players." ]
[ "aops_c6_high_school_olympiads" ]
[ "cot" ]
{ "cot": 14 }
14
0
0
omr-ws-7c13c842b515e53ac38f901bf598255ac6d4d0c77f2089b024c4acfe0c21dc23
Two players alternately replace the stars in the expression \[ *x^{2000} + *x^{1999} + \cdots + *x + 1 \] by real numbers. The player who makes the last move loses if the resulting polynomial has a real root \( t \) with \( |t| < 1 \), and wins otherwise. Give a winning strategy for one of the players.
[ "\\text{The second player has a winning strategy.}" ]
[ "Two players alternately replace the stars in the expression\n\\[ *x^{2000} + *x^{1999} + \\cdots + *x + 1 \\]\nby real numbers. The player who makes the last move loses if the resulting polynomial has a real root \\( t \\) with \\( |t| < 1 \\), and wins otherwise. Give a winning strategy for one of the players." ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 10, "genselect": 3 }
13
0
0
omr-ws-827989831701816ad3ef97f3242ba31f8bf60444048fbebc3df6a657e2a09479
Two players alternately replace the stars in the expression \[ *x^{2000} + *x^{1999} + \cdots + *x + 1 \] by real numbers. The player who makes the last move loses if the resulting polynomial has a real root \( t \) with \( |t| < 1 \), and wins otherwise. Provide a winning strategy for one of the players.
[ "The first player (A) has the winning strategy." ]
[ "Two players alternately replace the stars in the expression \n\\[ *x^{2000} + *x^{1999} + \\cdots + *x + 1 \\]\nby real numbers. The player who makes the last move loses if the resulting polynomial has a real root \\( t \\) with \\( |t| < 1 \\), and wins otherwise. Provide a winning strategy for one of the players...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect", "tir" ]
{ "cot": 4, "genselect": 6, "tir": 2 }
12
0
0
omr-ws-351bba9c86d9d0b0d851bf757ad6ced1c19c1842bca533e08e6d86856b201400
Two players alternately replace the stars in the polynomial expression \( *x^{2000} + *x^{1999} + \ldots + *x + 1 \) by real numbers until all stars are replaced. If the resulting polynomial has a real root, the first player wins; otherwise, the second player wins. Who has a winning strategy?
[ "\\text{First player}" ]
[ "Two players alternately replace the stars in the polynomial expression \\( *x^{2000} + *x^{1999} + \\ldots + *x + 1 \\) by real numbers until all stars are replaced. If the resulting polynomial has a real root, the first player wins; otherwise, the second player wins. Who has a winning strategy?" ]
[ "aops_c6_high_school_olympiads" ]
[ "genselect" ]
{ "genselect": 8 }
8
0
0
omr-ws-fd5495a888e2304e1b9cabe180813396ec4f539311d7a31ac01a6ff9f49975d0
Two players alternately roll an $N$-sided die. The player who fails to roll a number greater than the previous roll loses. What is the probability that the first player wins?
[ "1 - \\left( \\frac{N-1}{N} \\right)^N" ]
[ "Two players alternately roll an $N$-sided die. The player who fails to roll a number greater than the previous roll loses. What is the probability that the first player wins?" ]
[ "aops_c4_high_school_math" ]
[ "cot" ]
{ "cot": 15 }
15
0
0
omr-ws-f873817d83db607fe4a0e0d625418974056a458d10212c5405268afc0f41f48a
Two players alternately take turns removing 1, 2, 3, 4, or 5 stones from a pile of 2000 stones. A player cannot take the same number of stones as the previous player did on their last turn. The player who cannot make a valid move loses. Determine which player has a winning strategy and describe the strategy.
[ "First player wins by taking 4 stones initially." ]
[ "Two players alternately take turns removing 1, 2, 3, 4, or 5 stones from a pile of 2000 stones. A player cannot take the same number of stones as the previous player did on their last turn. The player who cannot make a valid move loses. Determine which player has a winning strategy and describe the strategy." ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect", "tir" ]
{ "cot": 30, "genselect": 6, "tir": 15 }
51
0
0
omr-ws-e79fe1d5ede76d397a7b9c1c9cfef0b7620dc9795d12b380205c266ebaf6be1c
Two players alternately write O's (first player) and X's (second player) in the unoccupied cells of an \( n \times n \) grid. The first player (if any) to occupy four cells at the vertices of a square with horizontal and vertical sides wins. What is the outcome of the game given best possible play by both players? Note...
[ "\\text{First player wins}" ]
[ "Two players alternately write O's (first player) and X's (second player) in the unoccupied cells of an \\( n \\times n \\) grid. The first player (if any) to occupy four cells at the vertices of a square with horizontal and vertical sides wins. What is the outcome of the game given best possible play by both playe...
[ "aops_c6_high_school_olympiads" ]
[ "cot" ]
{ "cot": 16 }
16
0
0
omr-ws-be12384c3333251916b18edd197241b6dc236429bb2360bc97be3deaa526d9b2
Two players alternately write O's (first player) and X's (second player) in the unoccupied cells of an \( n \times n \) grid. The first player to write four of his/her symbols at the vertices of a square with horizontal and vertical sides is the winner. What is the smallest \( n \) such that the first player has a winn...
[ "5" ]
[ "Two players alternately write O's (first player) and X's (second player) in the unoccupied cells of an \\( n \\times n \\) grid. The first player to write four of his/her symbols at the vertices of a square with horizontal and vertical sides is the winner. What is the smallest \\( n \\) such that the first player ...
[ "aops_c7_college_math" ]
[ "cot", "genselect" ]
{ "cot": 8, "genselect": 7 }
15
0
0
omr-ws-67096fd78f2f8369faf45476f00d052bc83e4c1a6fcd846dd1d5dead16f1e247
Two players alternately write divisors of $100!$ on a blackboard, ensuring no number is repeated. The player whose move results in the greatest common divisor (GCD) of all written numbers being $1$ loses the game. Which player has a winning strategy?
[ "The second player has a winning strategy." ]
[ "Two players alternately write divisors of $100!$ on a blackboard, ensuring no number is repeated. The player whose move results in the greatest common divisor (GCD) of all written numbers being $1$ loses the game. Which player has a winning strategy?" ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect", "tir" ]
{ "cot": 13, "genselect": 5, "tir": 13 }
31
0
0
omr-ws-432059e84387a4b4be46425e771e7d935b02d7d3219a44016ef31e5a78a28f20
Two players alternately write integers on a blackboard as follows: the first player writes \( a_{1} \) arbitrarily, then the second player writes \( a_{2} \) arbitrarily, and thereafter a player writes a number equal to the sum of the two preceding numbers. The player after whose move the obtained sequence contains ter...
[ "The second player has the winning strategy." ]
[ "Two players alternately write integers on a blackboard as follows: the first player writes \\( a_{1} \\) arbitrarily, then the second player writes \\( a_{2} \\) arbitrarily, and thereafter a player writes a number equal to the sum of the two preceding numbers. The player after whose move the obtained sequence con...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "tir" ]
{ "cot": 16, "tir": 20 }
36
0
0
omr-ws-5c28e50faa00235808874684c255383b5d54d1560817d3e413552b3bfb394d8e
Two players and a judge play a game. Each player picks a positive integer \( a \) and \( b \) and tells it to the judge. The judge then discloses \( a+b \) and another number \( x \). The judge takes turns asking both players if they can guess the other's number. Let \( N \) be the smallest number of questions after wh...
[ "2" ]
[ "Two players and a judge play a game. Each player picks a positive integer \\( a \\) and \\( b \\) and tells it to the judge. The judge then discloses \\( a+b \\) and another number \\( x \\). The judge takes turns asking both players if they can guess the other's number. Let \\( N \\) be the smallest number of que...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 4, "genselect": 3 }
7
0
0
omr-ws-b0ba06611c820cc713587ee7c789ebe5a827bc141c876fa15c0ff06857b35b9e
Two players are playing a blackjack machine where they can win or lose $1$ dollar at a time. Both players play once per minute and eventually both win exactly $2N$ dollars. Let $T$ be the length of the shortest time interval during which both players won exactly $N$ dollars. Find the maximum possible value of $T$ in te...
[ "3N" ]
[ "Two players are playing a blackjack machine where they can win or lose $1$ dollar at a time. Both players play once per minute and eventually both win exactly $2N$ dollars. Let $T$ be the length of the shortest time interval during which both players won exactly $N$ dollars. Find the maximum possible value of $T$ ...
[ "aops_c6_high_school_olympiads" ]
[ "cot" ]
{ "cot": 1 }
1
0
0
omr-ws-d5399b3a462b0e7655b30690263507f51a77b662a776ff1f1c155a9979e5dc56
Two players are playing a game in which $2n$ numbers are written on a board. Each turn, one player picks one of the numbers on the board, and the other player gets to choose which player to give the number to (the players alternate roles). The game ends when either player has $n$ numbers, at which point all remaining n...
[ "\\left\\lceil \\dfrac{n(2n +1)}{2} \\right\\rceil" ]
[ "Two players are playing a game in which $2n$ numbers are written on a board. Each turn, one player picks one of the numbers on the board, and the other player gets to choose which player to give the number to (the players alternate roles). The game ends when either player has $n$ numbers, at which point all remain...
[ "aops_c6_high_school_olympiads" ]
[ "additional_problems" ]
{ "additional_problems": 1 }
1
0
0
omr-ws-8e5f44af4596dfe8e742ea80f4a804b935e25c9be12a5b9931be3b8c028bcfc2
Two players are playing a game involving piles of coins. A legal move is to remove a coin or split a pile of coins into two non-empty piles. They are playing with piles of coins where the $k$-th pile contains $k$ coins. Determine which player has the winning strategy.
[ "\\text{First player}" ]
[ "Two players are playing a game involving piles of coins. A legal move is to remove a coin or split a pile of coins into two non-empty piles. They are playing with piles of coins where the $k$-th pile contains $k$ coins. Determine which player has the winning strategy." ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 15, "genselect": 8 }
23
0
0
omr-ws-849a46d857c4c72b23c5a6a2f24df96a6f0adbf363761a727da14fe2880a4a4e
Two players are playing a game on a $1403 \times 1403$ grid with $1403^2$ cells. The first player, on each turn, selects an unchosen cell and draws a vertical line segment from the top to the bottom of the cell. The second player, on each turn, selects an unchosen cell and draws a horizontal line segment from the left ...
[ "Draw" ]
[ "Two players are playing a game on a $1403 \\times 1403$ grid with $1403^2$ cells. The first player, on each turn, selects an unchosen cell and draws a vertical line segment from the top to the bottom of the cell. The second player, on each turn, selects an unchosen cell and draws a horizontal line segment from the...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect", "tir" ]
{ "cot": 5, "genselect": 3, "tir": 10 }
18
0
0
omr-ws-1f77b238aa6729dd0d358629768bc41d22cfd2c489cc986cd97898893f5e60c8
Two players are playing a game on a $1994 \times 1994$ board with a chess knight piece. Player 1 moves the knight two cells horizontally and one cell vertically, while Player 2 moves the knight two cells vertically and one cell horizontally. No player can move the knight to a cell that has already been used. Determine ...
[ "1988018" ]
[ "Two players are playing a game on a $1994 \\times 1994$ board with a chess knight piece. Player 1 moves the knight two cells horizontally and one cell vertically, while Player 2 moves the knight two cells vertically and one cell horizontally. No player can move the knight to a cell that has already been used. Dete...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 3, "genselect": 6 }
9
0
0
omr-ws-a925060ba8a43921e757574a6fec41c144869aff2eba80db928c8d7e6ac6a472
Two players are playing a game on a $2018 \times 2018$ board. The first player places blue coins, and the second player places red coins. The first player wins if they can create 5 blue coins in a row or column. Determine the minimum number of blue coins the first player must place to guarantee a win, assuming the seco...
[ "8073" ]
[ "Two players are playing a game on a $2018 \\times 2018$ board. The first player places blue coins, and the second player places red coins. The first player wins if they can create 5 blue coins in a row or column. Determine the minimum number of blue coins the first player must place to guarantee a win, assuming th...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 2, "genselect": 2 }
4
0
0
omr-ws-51d5cedc908758f913d55012ad9cd3e90d0bbbb39eb43d0d5ca9206c80def35f
Two players are playing a game on a 3x7 rectangle board $P$ and a set of tetrominoes $S$. Each player alternately chooses a tetromino from $S$ and places it on $P$ (possibly after rotation and/or reflection) such that each square on the tetromino is precisely above one square on $P$ and does not overlap with any previo...
[ "\\text{Second player}" ]
[ "Two players are playing a game on a 3x7 rectangle board $P$ and a set of tetrominoes $S$. Each player alternately chooses a tetromino from $S$ and places it on $P$ (possibly after rotation and/or reflection) such that each square on the tetromino is precisely above one square on $P$ and does not overlap with any p...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 10, "genselect": 4 }
14
0
0
omr-ws-6e724b8339804797338c7d4c528bfc473df319b66f5f8ce209361e2d9b539f1a
Two players are playing a game on a 4x5 rectangle board $P$ and a set of tetrominoes $S$. Each player alternately chooses a tetromino from $S$ and places it on $P$ (possibly after rotation and/or reflection) such that each square on the tetromino is precisely above one square on $P$ and does not overlap with any previo...
[ "\\text{Second player}" ]
[ "Two players are playing a game on a 4x5 rectangle board $P$ and a set of tetrominoes $S$. Each player alternately chooses a tetromino from $S$ and places it on $P$ (possibly after rotation and/or reflection) such that each square on the tetromino is precisely above one square on $P$ and does not overlap with any p...
[ "aops_c6_high_school_olympiads" ]
[ "cot" ]
{ "cot": 16 }
16
0
0
omr-ws-e4ccc25f9ec6748a94bcf05c642bdf8a51618f8ffef33ead26f00fdc04c68c95
Two players are playing a game on a circle with \( n \) points. On each move, a player chooses a point and connects it with an edge to either an adjacent point or the center of the circle. The winner is the player whose move ensures that every point (including the center) can be reached from any other point via the con...
[ "\\text{Second player}" ]
[ "Two players are playing a game on a circle with \\( n \\) points. On each move, a player chooses a point and connects it with an edge to either an adjacent point or the center of the circle. The winner is the player whose move ensures that every point (including the center) can be reached from any other point via ...
[ "aops_c6_high_school_olympiads" ]
[ "cot" ]
{ "cot": 9 }
9
0
0
omr-ws-e9a996357fe128c9ca5b0fc6dd57b33d38845c9e337918d26ee0927d0d4d8253
Two players are playing a game on a cross-shaped board $P$ (a central 3x3 square with a 3x3 square attached to each side) and a set of pentominoes $S$. Each player alternately chooses a pentomino from $S$ and places it on $P$ (possibly after rotation and/or reflection) such that each square on the pentomino is precisel...
[ "\\text{Second player}" ]
[ "Two players are playing a game on a cross-shaped board $P$ (a central 3x3 square with a 3x3 square attached to each side) and a set of pentominoes $S$. Each player alternately chooses a pentomino from $S$ and places it on $P$ (possibly after rotation and/or reflection) such that each square on the pentomino is pre...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 15, "genselect": 7 }
22
0
0
omr-ws-756409620e64c379dd4889cc0a5a25f0c18bacc6e565e6172325623d0f119863
Two players are playing a game on an 8x8 square board $P$ and a set of pentominoes $S$. Each player alternately chooses a pentomino from $S$ and places it on $P$ (possibly after rotation and/or reflection) such that each square on the pentomino is precisely above one square on $P$ and does not overlap with any previous...
[ "\\text{Second player}" ]
[ "Two players are playing a game on an 8x8 square board $P$ and a set of pentominoes $S$. Each player alternately chooses a pentomino from $S$ and places it on $P$ (possibly after rotation and/or reflection) such that each square on the pentomino is precisely above one square on $P$ and does not overlap with any pre...
[ "aops_c6_high_school_olympiads" ]
[ "cot" ]
{ "cot": 16 }
16
0
0
omr-ws-ed9c75b60f5e4b335be59dbeae44ffb3f5371103a61201b8024641a16caab8d8
Two players are playing a game where on each turn, a player writes a pair of non-negative integer numbers $(a,b)$ such that for each previously written pair $(c,d)$, either $a < c$ or $b < d$. The player who writes the pair $(0,0)$ loses. Determine which player wins if both players play optimally.
[ "\\text{First player}" ]
[ "Two players are playing a game where on each turn, a player writes a pair of non-negative integer numbers $(a,b)$ such that for each previously written pair $(c,d)$, either $a < c$ or $b < d$. The player who writes the pair $(0,0)$ loses. Determine which player wins if both players play optimally." ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 11, "genselect": 7 }
18
0
0
omr-ws-0d9354cc87769b8617b3dd99e389a6da887f45e272a0ca6e9405e51709a3f41e
Two players are playing a game where they color the sides of an $n$-gon polygon. Player 1 can color a side if 0 or 2 of the adjacent sides are already colored, and Player 2 can color a side if exactly 1 of the adjacent sides is already colored. The player who cannot color a side loses. Who has the winning strategy?
[ "Player 1 wins for \\( n \\neq 4 \\), Player 2 wins for \\( n = 4 \\)." ]
[ "Two players are playing a game where they color the sides of an $n$-gon polygon. Player 1 can color a side if 0 or 2 of the adjacent sides are already colored, and Player 2 can color a side if exactly 1 of the adjacent sides is already colored. The player who cannot color a side loses. Who has the winning strategy...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect", "tir" ]
{ "cot": 1, "genselect": 1, "tir": 13 }
15
0
0
omr-ws-c8c360dab58f1403d4201d0299c55fb0bba734a9cc92505ed438bd7e1b3c03c8
Two players are playing a game where they write down the divisors of the number \(2022! \times 2023!\) except 1 on the blackboard, taking turns. Each player must write a divisor that is different from 1 and all previously written numbers. A player loses if after their turn, there exists a pair of numbers on the blackbo...
[ "Player 1" ]
[ "Two players are playing a game where they write down the divisors of the number \\(2022! \\times 2023!\\) except 1 on the blackboard, taking turns. Each player must write a divisor that is different from 1 and all previously written numbers. A player loses if after their turn, there exists a pair of numbers on the...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect", "tir" ]
{ "cot": 12, "genselect": 7, "tir": 10 }
29
0
0
omr-ws-17b303abb8a4aa4de56c206abe3786291486ed2ecf96560ba37cf0c46ea791d0
Two players are playing a game with 11 quadratic equations of the form $\star x^2 + \star x + \star = 0$. Each player takes turns replacing one star with a real nonzero number. The first player aims to maximize the number of equations without real roots, while the second player aims to minimize this number. What is the...
[ "6" ]
[ "Two players are playing a game with 11 quadratic equations of the form $\\star x^2 + \\star x + \\star = 0$. Each player takes turns replacing one star with a real nonzero number. The first player aims to maximize the number of equations without real roots, while the second player aims to minimize this number. Wha...
[ "aops_c4_high_school_math" ]
[ "cot", "genselect" ]
{ "cot": 13, "genselect": 2 }
15
0
0
omr-ws-3a26f5429e68babf16efa5cd4869671ca23676ffef3707bcbdbb9e449b2da094
Two players are playing a game with an $N \times M$ grid of empty squares. On each turn, a player fills in a single empty square, then fills in all the squares in the same row, and then fills in all the squares in the same column. The players alternate taking turns until all squares are filled in. Let $f(N, M)$ be the ...
[ "0" ]
[ "Two players are playing a game with an $N \\times M$ grid of empty squares. On each turn, a player fills in a single empty square, then fills in all the squares in the same row, and then fills in all the squares in the same column. The players alternate taking turns until all squares are filled in. Let $f(N, M)$ b...
[ "aops_c6_high_school_olympiads" ]
[ "additional_problems" ]
{ "additional_problems": 1 }
1
0
0
omr-ws-fa3ec6825ebb4e1efbe7f75e9faaae42784315cc0fbad579d5b098d0df3d196f
Two players are playing a game. Player 1 picks three different non-zero numbers \(a\), \(b\), and \(c\). Player 2 substitutes these numbers into the equation \(x^2 + *x + * = 0\) in any order. Player 2 aims to ensure the resulting quadratic equation has two distinct roots. If Player 2 succeeds, they win. Determine the ...
[ "2" ]
[ "Two players are playing a game. Player 1 picks three different non-zero numbers \\(a\\), \\(b\\), and \\(c\\). Player 2 substitutes these numbers into the equation \\(x^2 + *x + * = 0\\) in any order. Player 2 aims to ensure the resulting quadratic equation has two distinct roots. If Player 2 succeeds, they win. D...
[ "aops_c6_high_school_olympiads" ]
[ "additional_problems" ]
{ "additional_problems": 1 }
1
0
0
omr-ws-d0f59a2c7f0c62669169665f05df0da3e67a8e17c7cb91f531d538f368e48252
Two players are playing a number subtraction game using two four-digit numbers. The first player calls out a digit between 0 and 9 (these may be repeated), and the second player places it in any free space. The first player tries to make the difference as large as possible, while the second tries to make the difference...
[ "8001" ]
[ "Two players are playing a number subtraction game using two four-digit numbers. The first player calls out a digit between 0 and 9 (these may be repeated), and the second player places it in any free space. The first player tries to make the difference as large as possible, while the second tries to make the diffe...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 1, "genselect": 1 }
2
0
0
omr-ws-1d22b25174596f36239149ffdd1dd2f55929ac03db920b24d81af24fdc60d481
Two players are playing a turn-based game on an $n \times n$ chessboard. At the beginning, only the bottom left corner of the chessboard contains a piece. At each turn, the player moves the piece to either the square just above, or the square just right, or the diagonal square just right-top. If a player cannot make a ...
[ "4" ]
[ "Two players are playing a turn-based game on an $n \\times n$ chessboard. At the beginning, only the bottom left corner of the chessboard contains a piece. At each turn, the player moves the piece to either the square just above, or the square just right, or the diagonal square just right-top. If a player cannot m...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect", "tir" ]
{ "cot": 10, "genselect": 7, "tir": 3 }
20
0
0
omr-ws-71396a71cdc735288cf7ad21a6a3cc8ec0f73473077d4c5b6c7fc35f4598a62c
Two players are playing chess, and each player's clock starts and stops as described in the original problem. After each player has made 40 moves, both clocks read exactly 150 minutes. Calculate the minimum difference in seconds that must have occurred between the two clocks at some point during the game.
[ "225" ]
[ "Two players are playing chess, and each player's clock starts and stops as described in the original problem. After each player has made 40 moves, both clocks read exactly 150 minutes. Calculate the minimum difference in seconds that must have occurred between the two clocks at some point during the game." ]
[ "aops_c6_high_school_olympiads" ]
[ "cot" ]
{ "cot": 7 }
7
0
0
omr-ws-269ded1ac432fed5a484a36758845d0116e7dd851ed874e9f7756f4f538b1f73
Two players are throwing a six-sided die. If the first player rolls a 6, he loses and the game is over. If not, the second player throws the die. If the second player rolls a 6, he loses and the game is over; otherwise, the first player throws again. The game continues until one player rolls a 6 and loses, with the oth...
[ "\\(\\frac{6}{11}\\)" ]
[ "Two players are throwing a six-sided die. If the first player rolls a 6, he loses and the game is over. If not, the second player throws the die. If the second player rolls a 6, he loses and the game is over; otherwise, the first player throws again. The game continues until one player rolls a 6 and loses, with th...
[ "aops_c4_high_school_math" ]
[ "cot", "tir" ]
{ "cot": 16, "tir": 28 }
44
0
0
omr-ws-4f913b9e1d04112e66cfdc08add396ca4f028204030bccfd9b8e2028789b3958
Two players compete in a game with N > 2 stacks, each containing one stone. On each turn, a player can combine two stacks such that the total number of stones in the combined stacks is a prime number. The player who cannot make a move loses. Find a winning strategy.
[ "The second player has a winning strategy." ]
[ "Two players compete in a game with N > 2 stacks, each containing one stone. On each turn, a player can combine two stacks such that the total number of stones in the combined stacks is a prime number. The player who cannot make a move loses. Find a winning strategy." ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect", "tir" ]
{ "cot": 23, "genselect": 5, "tir": 12 }
40
0
0
omr-ws-f3f5f183803626bc45d78a9f334cb8b5014f41cdbaf2fe47864da5cb4d50099e
Two players continue playing rock-paper-scissors games until one of them wins the third time. Each player selects rock, paper, or scissors at random with equal probability $\frac{1}{3}$ for each choice. Determine the expected value of the number of games needed.
[ "\\dfrac{99}{16}" ]
[ "Two players continue playing rock-paper-scissors games until one of them wins the third time. Each player selects rock, paper, or scissors at random with equal probability $\\frac{1}{3}$ for each choice. Determine the expected value of the number of games needed." ]
[ "aops_c6_high_school_olympiads" ]
[ "cot" ]
{ "cot": 16 }
16
0
0
omr-ws-2277cd841b86e58fc943c655eddd90cda38117ef5dbe3f4ef750e8b3766a647e
Two players each have a knight on a band of length $N$. Player 1 rolls a 6-sided die, multiplies the result by 2, and moves their knight that distance. Player 2 rolls the die twice, adds the results, and moves their knight that distance. The winner is the player whose knight passes the band after fewer steps. Assuming ...
[ "Player 1" ]
[ "Two players each have a knight on a band of length $N$. Player 1 rolls a 6-sided die, multiplies the result by 2, and moves their knight that distance. Player 2 rolls the die twice, adds the results, and moves their knight that distance. The winner is the player whose knight passes the band after fewer steps. Assu...
[ "aops_c7_college_math" ]
[ "cot", "genselect" ]
{ "cot": 11, "genselect": 4 }
15
0
0
omr-ws-aafb5be822b18e9d1ab372fad08fbfe731a5d9e3e1aa2fd26e986909ec9f4962
Two players each have a knight on a chessboard. Each player takes turns moving their knight to an unvisited square. The player who cannot move to a new square loses. Determine which player can win and describe the winning strategy.
[ "\\text{The second player can always win by mirroring the first player's moves across the board's center.}" ]
[ "Two players each have a knight on a chessboard. Each player takes turns moving their knight to an unvisited square. The player who cannot move to a new square loses. Determine which player can win and describe the winning strategy." ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 13, "genselect": 3 }
16
0
0
omr-ws-9ef1bebbc3800854c9930f0837fed8a0f3ee0ad2c846a3174e7d1ab1b2dab94f
Two players each own $n$ dollars and are bidding for an object of value $c > 0$. Each player makes a sealed bid, offering $i$ dollars (where $i$ is an integer from $0$ to $n$) for the sole possession of the object. The higher bidder gets the object and pays the other player the amount they bid. If both bid the same amo...
[ "The payoff matrix has a saddle point at \\( \\lfloor c \\rfloor \\)." ]
[ "Two players each own $n$ dollars and are bidding for an object of value $c > 0$. Each player makes a sealed bid, offering $i$ dollars (where $i$ is an integer from $0$ to $n$) for the sole possession of the object. The higher bidder gets the object and pays the other player the amount they bid. If both bid the sam...
[ "aops_c7_college_math" ]
[ "cot", "genselect", "tir" ]
{ "cot": 14, "genselect": 4, "tir": 6 }
24
0
0
omr-ws-4d15b89e983fdd8c4a09b16b38f87c8fe25b9f2ae32c1cdc3ed470683eb74784
Two players each roll a pair of standard four-sided dice. The rolls for the first player are \(a_1\) and \(a_2\) with \(a_1 \le a_2\) and the rolls for the second player are \(b_1\) and \(b_2\) with \(b_1 \le b_2\). The probability that \(a_1 > b_1\) and \(a_2 > b_2\) can be expressed as \(\frac{a}{b}\) where \(a\) and...
[ "\\(\\frac{23}{128}\\)" ]
[ "Two players each roll a pair of standard four-sided dice. The rolls for the first player are \\(a_1\\) and \\(a_2\\) with \\(a_1 \\le a_2\\) and the rolls for the second player are \\(b_1\\) and \\(b_2\\) with \\(b_1 \\le b_2\\). The probability that \\(a_1 > b_1\\) and \\(a_2 > b_2\\) can be expressed as \\(\\fra...
[ "aops_c4_high_school_math", "c4_high_school_math" ]
[ "cot", "genselect", "tir" ]
{ "cot": 13, "genselect": 8, "tir": 24 }
45
0
0
omr-ws-e9f5b0da3c7ec54dcaa9181e72af46c060079b1ab72f05e398fefb9ab4567daf
Two players fill an $n \times n$ square board with $0$ and $1$. After the board is filled, they calculate the sum $r_i$ of numbers in the $i$th row and $c_i$ of numbers in the $i$th column. Let \[ R = \sum_{i=1}^{n} i r_i, \quad C = \sum_{i=1}^{n} i c_i. \] The first player wins if $R < C$, and the second player wins o...
[ "Neither player has a winning strategy." ]
[ "Two players fill an $n \\times n$ square board with $0$ and $1$. After the board is filled, they calculate the sum $r_i$ of numbers in the $i$th row and $c_i$ of numbers in the $i$th column. Let\n\n\\[ R = \\sum_{i=1}^{n} i r_i, \\quad C = \\sum_{i=1}^{n} i c_i. \\]\n\nThe first player wins if $R < C$, and the sec...
[ "aops_c6_high_school_olympiads" ]
[ "additional_problems" ]
{ "additional_problems": 1 }
1
0
0
omr-ws-5d98f84942159c32d7f347bd618bfe6e6cb864e6a8f6ce816f06a68bcbf5040b
Two players have 4 sets of coins with 1, 3, 5, and 7 coins in them. On each turn, a player can select any number of coins but only from one of these 4 sets. The player who must take the last coin loses. Determine if there is a winning strategy for either player.
[ "Second player has a winning strategy." ]
[ "Two players have 4 sets of coins with 1, 3, 5, and 7 coins in them. On each turn, a player can select any number of coins but only from one of these 4 sets. The player who must take the last coin loses. Determine if there is a winning strategy for either player." ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "tir" ]
{ "cot": 16, "tir": 26 }
42
0
0
omr-ws-d11fffc942e7700ccf0baf840f68634b1807d4ead2912bb85e58c379e9a8aa4d
Two players have sets of coins with 1, 3, 5, ..., 2n-1 coins in them. On each turn, a player can select any number of coins but only from one of these sets. The player who must take the last coin loses. Determine if there is a winning strategy for either player.
[ "The first player has a winning strategy if \\( n \\) is not a power of 2; otherwise, the second player has a winning strategy." ]
[ "Two players have sets of coins with 1, 3, 5, ..., 2n-1 coins in them. On each turn, a player can select any number of coins but only from one of these sets. The player who must take the last coin loses. Determine if there is a winning strategy for either player." ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "tir" ]
{ "cot": 1, "tir": 11 }
12
0
0
omr-ws-cc3f8182a3cc94b06e3dbf95fdcf489324f99bf9ded33f516e1b6525c7694cce
Two players have three piles of rocks, one with 50 rocks, another with 60 rocks, and the last one with 70 rocks. They take turns, and in each turn, a player must split a pile with at least 2 rocks into two piles (not necessarily of equal size). The player who cannot make a move loses. Determine which player has the win...
[ "The first player has the winning strategy." ]
[ "Two players have three piles of rocks, one with 50 rocks, another with 60 rocks, and the last one with 70 rocks. They take turns, and in each turn, a player must split a pile with at least 2 rocks into two piles (not necessarily of equal size). The player who cannot make a move loses. Determine which player has th...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "tir" ]
{ "cot": 16, "tir": 29 }
45
0
0
omr-ws-f9cf8321f3795fd731c120309067202c1a146efeb608aa8a0c448e928ca8b0b8
Two players in turn paint cells of a \(7 \times 7\) table each using their own color. A player cannot paint a cell if its row or its column contains a cell painted by the other player. The game stops when one of the players cannot make their turn. What is the maximal number of cells that can remain unpainted when the g...
[ "25", "36" ]
[ "Two players in turn paint cells of a \\(7 \\times 7\\) table each using their own color. A player cannot paint a cell if its row or its column contains a cell painted by the other player. The game stops when one of the players cannot make their turn. What is the maximal number of cells that can remain unpainted wh...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect", "tir" ]
{ "cot": 9, "genselect": 3, "tir": 1 }
13
0
0
omr-ws-b9047a45a87f7e5f72500975c5e1f252aefeb2a22d8a9c4660323e78a8d00949
Two players in turn put two or three coins into their own hats (before the game starts, the hats are empty). Each time, after both players made five moves, they exchange hats. The player wins if after his move his hat contains one hundred or more coins. Which player has a winning strategy?
[ "The player who places fewer coins has a winning strategy." ]
[ "Two players in turn put two or three coins into their own hats (before the game starts, the hats are empty). Each time, after both players made five moves, they exchange hats. The player wins if after his move his hat contains one hundred or more coins. Which player has a winning strategy?" ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 6, "genselect": 1 }
7
0
0
omr-ws-a0f6851207774f3c9405bc8a9026ae8becf32d977381d8d85edf44a600a6233f
Two players in turn put two or three coins into their own hats (before the game starts, the hats are empty). Each time, after the second player duplicated the move of the first player, they exchange hats. The player wins if after his move his hat contains one hundred or more coins. Which player has a winning strategy?
[ "Player 1 has a winning strategy." ]
[ "Two players in turn put two or three coins into their own hats (before the game starts, the hats are empty). Each time, after the second player duplicated the move of the first player, they exchange hats. The player wins if after his move his hat contains one hundred or more coins. Which player has a winning strat...
[ "aops_c6_high_school_olympiads", "c6_high_school_olympiads" ]
[ "cot", "genselect", "tir" ]
{ "cot": 9, "genselect": 8, "tir": 10 }
27
0
0
omr-ws-6e3f98cb2fca191cf523bdcb2c903adf9732b2ff5dd1bde62ef3c47f6043058c
Two players in turns color the sides of an $n$-gon. The first player colors any side that has $0$ or $2$ common vertices with already colored sides. The second player colors any side that has exactly $1$ common vertex with already colored sides. The player who cannot move, loses. For which $n$ does the second player ha...
[ "n \\equiv 0 \\pmod{4}" ]
[ "Two players in turns color the sides of an $n$-gon. The first player colors any side that has $0$ or $2$ common vertices with already colored sides. The second player colors any side that has exactly $1$ common vertex with already colored sides. The player who cannot move, loses. For which $n$ does the second play...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 11, "genselect": 1 }
12
0
0
omr-ws-9178c67348c540640cba6f655eb7c9fbf282b4ed5337afd5e367a192fc9c4019
Two players move alternately, starting with several piles of chips. A move consists of splitting every pile with more than one chip into two piles. The player who makes the last move wins. For what initial conditions does the first player win, and what is his winning strategy?
[ "\\text{The first player wins if and only if there is at least one even-sized pile initially.}" ]
[ "Two players move alternately, starting with several piles of chips. A move consists of splitting every pile with more than one chip into two piles. The player who makes the last move wins. For what initial conditions does the first player win, and what is his winning strategy?" ]
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 6, "genselect": 5 }
11
0
0
omr-ws-c56b9c7dafb5acdc9435dedff050cd3b8327a6f44437a64f31eb758a9db80dbf
Two players play a card game with a deck of $n$ distinct cards. For any two cards, it is known which one beats the other (the relation is not necessarily transitive). The deck is split between the players in an arbitrary manner. In each turn, each player reveals the top card from their deck, and the player whose card b...
[ "45" ]
[ "Two players play a card game with a deck of $n$ distinct cards. For any two cards, it is known which one beats the other (the relation is not necessarily transitive). The deck is split between the players in an arbitrary manner. In each turn, each player reveals the top card from their deck, and the player whose c...
[ "aops_c6_high_school_olympiads" ]
[ "cot", "genselect" ]
{ "cot": 4, "genselect": 6 }
10
0
0