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app_data_1600
One day Squidward, Spongebob and Patrick decided to go to the beach. Unfortunately, the weather was bad, so the friends were unable to ride waves. However, they decided to spent their time building sand castles. At the end of the day there were n castles built by friends. Castles are numbered from 1 to n, and the heig...
app_data_1601
This is a harder version of the problem. In this version, $n \le 50\,000$. There are $n$ distinct points in three-dimensional space numbered from $1$ to $n$. The $i$-th point has coordinates $(x_i, y_i, z_i)$. The number of points $n$ is even. You'd like to remove all $n$ points using a sequence of $\frac{n}{2}$ snap...
app_data_1602
Anu has created her own function $f$: $f(x, y) = (x | y) - y$ where $|$ denotes the bitwise OR operation. For example, $f(11, 6) = (11|6) - 6 = 15 - 6 = 9$. It can be proved that for any nonnegative numbers $x$ and $y$ value of $f(x, y)$ is also nonnegative. She would like to research more about this function and has...
app_data_1603
Kuriyama Mirai has killed many monsters and got many (namely n) stones. She numbers the stones from 1 to n. The cost of the i-th stone is v_{i}. Kuriyama Mirai wants to know something about these stones so she will ask you two kinds of questions: She will tell you two numbers, l and r (1 ≤ l ≤ r ≤ n), and you should t...
app_data_1604
Ori and Sein have overcome many difficult challenges. They finally lit the Shrouded Lantern and found Gumon Seal, the key to the Forlorn Ruins. When they tried to open the door to the ruins... nothing happened. Ori was very surprised, but Sein gave the explanation quickly: clever Gumon decided to make an additional de...
app_data_1605
We call a string good, if after merging all the consecutive equal characters, the resulting string is palindrome. For example, "aabba" is good, because after the merging step it will become "aba". Given a string, you have to find two values: the number of good substrings of even length; the number of good substrings...
app_data_1606
Little Chris is a huge fan of linear algebra. This time he has been given a homework about the unusual square of a square matrix. The dot product of two integer number vectors x and y of size n is the sum of the products of the corresponding components of the vectors. The unusual square of an n × n square matrix A is ...
app_data_1607
You are given a grid, consisting of $2$ rows and $n$ columns. Each cell of this grid should be colored either black or white. Two cells are considered neighbours if they have a common border and share the same color. Two cells $A$ and $B$ belong to the same component if they are neighbours, or if there is a neighbour ...
app_data_1608
Let's call a non-empty sequence of positive integers a_1, a_2... a_{k} coprime if the greatest common divisor of all elements of this sequence is equal to 1. Given an array a consisting of n positive integers, find the number of its coprime subsequences. Since the answer may be very large, print it modulo 10^9 + 7. N...
app_data_1609
Companies always have a lot of equipment, furniture and other things. All of them should be tracked. To do this, there is an inventory number assigned with each item. It is much easier to create a database by using those numbers and keep the track of everything. During an audit, you were surprised to find out that the...
app_data_1610
Permutation p is an ordered set of integers p_1, p_2, ..., p_{n}, consisting of n distinct positive integers, each of them doesn't exceed n. We'll denote the i-th element of permutation p as p_{i}. We'll call number n the size or the length of permutation p_1, p_2, ..., p_{n}. The decreasing coefficient of permu...
app_data_1611
[Image] As some of you know, cubism is a trend in art, where the problem of constructing volumetrical shape on a plane with a combination of three-dimensional geometric shapes comes to the fore. A famous sculptor Cicasso, whose self-portrait you can contemplate, hates cubism. He is more impressed by the idea to tra...
app_data_1612
Lately, a national version of a bingo game has become very popular in Berland. There are n players playing the game, each player has a card with numbers. The numbers on each card are distinct, but distinct cards can have equal numbers. The card of the i-th player contains m_{i} numbers. During the game the host takes ...
app_data_1613
Память компьютера состоит из n ячеек, которые выстроены в ряд. Пронумеруем ячейки от 1 до n слева направо. Про каждую ячейку известно, свободна она или принадлежит какому-либо процессу (в таком случае известен процесс, которому она принадлежит). Для каждого процесса известно, что принадлежащие ему ячейки занимают в па...
app_data_1614
Vanya and his friends are walking along the fence of height h and they do not want the guard to notice them. In order to achieve this the height of each of the friends should not exceed h. If the height of some person is greater than h he can bend down and then he surely won't be noticed by the guard. The height of the...
app_data_1615
Little penguin Polo adores integer segments, that is, pairs of integers [l; r] (l ≤ r). He has a set that consists of n integer segments: [l_1; r_1], [l_2; r_2], ..., [l_{n}; r_{n}]. We know that no two segments of this set intersect. In one move Polo can either widen any segment of the set 1 unit to the left or 1 un...
app_data_1616
You are given an array $a$ of length $n$ that has a special condition: every element in this array has at most 7 divisors. Find the length of the shortest non-empty subsequence of this array product of whose elements is a perfect square. A sequence $a$ is a subsequence of an array $b$ if $a$ can be obtained from $b$ b...
app_data_1617
There are $n$ people sitting in a circle, numbered from $1$ to $n$ in the order in which they are seated. That is, for all $i$ from $1$ to $n-1$, the people with id $i$ and $i+1$ are adjacent. People with id $n$ and $1$ are adjacent as well. The person with id $1$ initially has a ball. He picks a positive integer $k$ ...
app_data_1618
Dima's got a staircase that consists of n stairs. The first stair is at height a_1, the second one is at a_2, the last one is at a_{n} (1 ≤ a_1 ≤ a_2 ≤ ... ≤ a_{n}). Dima decided to play with the staircase, so he is throwing rectangular boxes at the staircase from above. The i-th box has width w_{i} and height h_{i}....
app_data_1619
Cowboy Beblop is a funny little boy who likes sitting at his computer. He somehow obtained two elastic hoops in the shape of 2D polygons, which are not necessarily convex. Since there's no gravity on his spaceship, the hoops are standing still in the air. Since the hoops are very elastic, Cowboy Beblop can stretch, rot...
app_data_1620
In the beginning of the new year Keivan decided to reverse his name. He doesn't like palindromes, so he changed Naviek to Navick. He is too selfish, so for a given n he wants to obtain a string of n characters, each of which is either 'a', 'b' or 'c', with no palindromes of length 3 appearing in the string as a substr...
app_data_1621
DZY loves collecting special strings which only contain lowercase letters. For each lowercase letter c DZY knows its value w_{c}. For each special string s = s_1s_2... s_{|}s| (|s| is the length of the string) he represents its value with a function f(s), where $f(s) = \sum_{i = 1}^{|s|}(w_{s_{i}} \cdot i)$ Now DZY ha...
app_data_1622
There are n employees working in company "X" (let's number them from 1 to n for convenience). Initially the employees didn't have any relationships among each other. On each of m next days one of the following events took place: either employee y became the boss of employee x (at that, employee x didn't have a boss be...
app_data_1623
Mislove had an array $a_1$, $a_2$, $\cdots$, $a_n$ of $n$ positive integers, but he has lost it. He only remembers the following facts about it: The number of different numbers in the array is not less than $l$ and is not greater than $r$; For each array's element $a_i$ either $a_i = 1$ or $a_i$ is even and there...
app_data_1624
Lunar New Year is approaching, and Bob is struggling with his homework – a number division problem. There are $n$ positive integers $a_1, a_2, \ldots, a_n$ on Bob's homework paper, where $n$ is always an even number. Bob is asked to divide those numbers into groups, where each group must contain at least $2$ numbers. ...
app_data_1625
Ilya is a very good-natured lion. He likes maths. Of all mathematical objects, his favourite one is matrices. Now he's faced a complicated matrix problem he needs to solve. He's got a square 2^{n} × 2^{n}-sized matrix and 4^{n} integers. You need to arrange all these numbers in the matrix (put each number in a single ...
app_data_1626
Pasha has recently bought a new phone jPager and started adding his friends' phone numbers there. Each phone number consists of exactly n digits. Also Pasha has a number k and two sequences of length n / k (n is divisible by k) a_1, a_2, ..., a_{n} / k and b_1, b_2, ..., b_{n} / k. Let's split the phone number into bl...
app_data_1627
Little Robber Girl likes to scare animals in her zoo for fun. She decided to arrange the animals in a row in the order of non-decreasing height. However, the animals were so scared that they couldn't stay in the right places. The robber girl was angry at first, but then she decided to arrange the animals herself. She ...
app_data_1628
Little Vitaly loves different algorithms. Today he has invented a new algorithm just for you. Vitaly's algorithm works with string s, consisting of characters "x" and "y", and uses two following operations at runtime: Find two consecutive characters in the string, such that the first of them equals "y", and the second...
app_data_1629
Little Vasya had n boxes with balls in the room. The boxes stood in a row and were numbered with numbers from 1 to n from left to right. Once Vasya chose one of the boxes, let's assume that its number is i, took all balls out from it (it is guaranteed that this box originally had at least one ball), and began putting ...
app_data_1630
Innokenty is a president of a new football league in Byteland. The first task he should do is to assign short names to all clubs to be shown on TV next to the score. Of course, the short names should be distinct, and Innokenty wants that all short names consist of three letters. Each club's full name consist of two wo...
app_data_1631
Fox Ciel is going to publish a paper on FOCS (Foxes Operated Computer Systems, pronounce: "Fox"). She heard a rumor: the authors list on the paper is always sorted in the lexicographical order. After checking some examples, she found out that sometimes it wasn't true. On some papers authors' names weren't sorted in l...
app_data_1632
Andrew and Jerry are playing a game with Harry as the scorekeeper. The game consists of three rounds. In each round, Andrew and Jerry draw randomly without replacement from a jar containing n balls, each labeled with a distinct positive integer. Without looking, they hand their balls to Harry, who awards the point to t...
app_data_1633
Pasha loves his phone and also putting his hair up... But the hair is now irrelevant. Pasha has installed a new game to his phone. The goal of the game is following. There is a rectangular field consisting of n row with m pixels in each row. Initially, all the pixels are colored white. In one move, Pasha can choose an...
app_data_1634
Vasya often uses public transport. The transport in the city is of two types: trolleys and buses. The city has n buses and m trolleys, the buses are numbered by integers from 1 to n, the trolleys are numbered by integers from 1 to m. Public transport is not free. There are 4 types of tickets: A ticket for one ride o...
app_data_1635
Vlad likes to eat in cafes very much. During his life, he has visited cafes n times. Unfortunately, Vlad started to feel that his last visits are not any different from each other. To fix that Vlad had a small research. First of all, Vlad assigned individual indices to all cafes. Then, he wrote down indices of cafes h...
app_data_1636
Wilbur is playing with a set of n points on the coordinate plane. All points have non-negative integer coordinates. Moreover, if some point (x, y) belongs to the set, then all points (x', y'), such that 0 ≤ x' ≤ x and 0 ≤ y' ≤ y also belong to this set. Now Wilbur wants to number the points in the set he has, that is ...
app_data_1637
Zibi is a competitive programming coach. There are $n$ competitors who want to be prepared well. The training contests are quite unusual – there are two people in a team, two problems, and each competitor will code exactly one of them. Of course, people in one team will code different problems. Rules of scoring also a...
app_data_1638
This is an easier version of the problem. In this version $n \le 1000$ The outskirts of the capital are being actively built up in Berland. The company "Kernel Panic" manages the construction of a residential complex of skyscrapers in New Berlskva. All skyscrapers are built along the highway. It is known that the comp...
app_data_1639
Kefa decided to make some money doing business on the Internet for exactly n days. He knows that on the i-th day (1 ≤ i ≤ n) he makes a_{i} money. Kefa loves progress, that's why he wants to know the length of the maximum non-decreasing subsegment in sequence a_{i}. Let us remind you that the subsegment of the sequence...
app_data_1640
Let's denote a function $d(x, y) = \left\{\begin{array}{ll}{y - x,} & {\text{if}|x - y|> 1} \\{0,} & {\text{if}|x - y|\leq 1} \end{array} \right.$ You are given an array a consisting of n integers. You have to calculate the sum of d(a_{i}, a_{j}) over all pairs (i, j) such that 1 ≤ i ≤ j ≤ n. -----Input----- The ...
app_data_1641
Vasya is currently at a car rental service, and he wants to reach cinema. The film he has bought a ticket for starts in t minutes. There is a straight road of length s from the service to the cinema. Let's introduce a coordinate system so that the car rental service is at the point 0, and the cinema is at the point s. ...
app_data_1642
You are given a convex polygon P with n distinct vertices p_1, p_2, ..., p_{n}. Vertex p_{i} has coordinates (x_{i}, y_{i}) in the 2D plane. These vertices are listed in clockwise order. You can choose a real number D and move each vertex of the polygon a distance of at most D from their original positions. Find the ...
app_data_1643
The only difference between easy and hard versions is the length of the string. You can hack this problem if you solve it. But you can hack the previous problem only if you solve both problems. Kirk has a binary string $s$ (a string which consists of zeroes and ones) of length $n$ and he is asking you to find a binary...
app_data_1644
Of course you have heard the famous task about Hanoi Towers, but did you know that there is a special factory producing the rings for this wonderful game? Once upon a time, the ruler of the ancient Egypt ordered the workers of Hanoi Factory to create as high tower as possible. They were not ready to serve such a strang...
app_data_1645
Eugene likes working with arrays. And today he needs your help in solving one challenging task. An array $c$ is a subarray of an array $b$ if $c$ can be obtained from $b$ by deletion of several (possibly, zero or all) elements from the beginning and several (possibly, zero or all) elements from the end. Let's call a ...
app_data_1646
String can be called correct if it consists of characters "0" and "1" and there are no redundant leading zeroes. Here are some examples: "0", "10", "1001". You are given a correct string s. You can perform two different operations on this string: swap any pair of adjacent characters (for example, "101" $\rightarrow...
app_data_1647
Valya and Tolya are an ideal pair, but they quarrel sometimes. Recently, Valya took offense at her boyfriend because he came to her in t-shirt with lettering that differs from lettering on her pullover. Now she doesn't want to see him and Tolya is seating at his room and crying at her photos all day long. This story c...
app_data_1648
There are K blue balls and N-K red balls. The balls of the same color cannot be distinguished. Snuke and Takahashi are playing with these balls. First, Snuke will arrange the N balls in a row from left to right. Then, Takahashi will collect only the K blue balls. In one move, he can collect any number of consecutive bl...
app_data_1649
Snuke has four cookies with deliciousness A, B, C, and D. He will choose one or more from those cookies and eat them. Is it possible that the sum of the deliciousness of the eaten cookies is equal to that of the remaining cookies? -----Constraints----- - All values in input are integers. - 1 \leq A,B,C,D \leq 10^{8}...
app_data_1650
You are given a positive integer L in base two. How many pairs of non-negative integers (a, b) satisfy the following conditions? - a + b \leq L - a + b = a \mbox{ XOR } b Since there can be extremely many such pairs, print the count modulo 10^9 + 7. What is XOR? The XOR of integers A and B, A \mbox{ XOR } B, is defi...
app_data_1651
Given are integers S and P. Is there a pair of positive integers (N,M) such that N + M = S and N \times M = P? -----Constraints----- - All values in input are integers. - 1 \leq S,P \leq 10^{12} -----Input----- Input is given from Standard Input in the following format: S P -----Output----- If there is a pair of p...
app_data_1652
You are given a string S consisting of lowercase English letters. Another string T is initially empty. Determine whether it is possible to obtain S = T by performing the following operation an arbitrary number of times: - Append one of the following at the end of T: dream, dreamer, erase and eraser. -----Constraints-...
app_data_1653
Alice has a string consisting of characters 'A', 'B' and 'C'. Bob can use the following transitions on any substring of our string in any order any number of times: A $\rightarrow$ BC B $\rightarrow$ AC C $\rightarrow$ AB AAA $\rightarrow$ empty string Note that a substring is one or more consecutive characters....
app_data_1654
You are given two strings s and t consisting of small Latin letters, string s can also contain '?' characters. Suitability of string s is calculated by following metric: Any two letters can be swapped positions, these operations can be performed arbitrary number of times over any pair of positions. Among all resulti...
app_data_1655
Hands that shed innocent blood! There are n guilty people in a line, the i-th of them holds a claw with length L_{i}. The bell rings and every person kills some of people in front of him. All people kill others at the same time. Namely, the i-th person kills the j-th person if and only if j < i and j ≥ i - L_{i}. You...
app_data_1656
Recall that string $a$ is a subsequence of a string $b$ if $a$ can be obtained from $b$ by deletion of several (possibly zero or all) characters. For example, for the string $a$="wowwo", the following strings are subsequences: "wowwo", "wowo", "oo", "wow", "", and others, but the following are not subsequences: "owoo",...
app_data_1657
You have n devices that you want to use simultaneously. The i-th device uses a_{i} units of power per second. This usage is continuous. That is, in λ seconds, the device will use λ·a_{i} units of power. The i-th device currently has b_{i} units of power stored. All devices can store an arbitrary amount of power. You ...
app_data_1658
When Darth Vader gets bored, he sits down on the sofa, closes his eyes and thinks of an infinite rooted tree where each node has exactly n sons, at that for each node, the distance between it an its i-th left child equals to d_{i}. The Sith Lord loves counting the number of nodes in the tree that are at a distance at m...
app_data_1659
After their adventure with the magic mirror Kay and Gerda have returned home and sometimes give free ice cream to kids in the summer. At the start of the day they have x ice cream packs. Since the ice cream is free, people start standing in the queue before Kay and Gerda's house even in the night. Each person in the q...
app_data_1660
Pashmak's homework is a problem about graphs. Although he always tries to do his homework completely, he can't solve this problem. As you know, he's really weak at graph theory; so try to help him in solving the problem. You are given a weighted directed graph with n vertices and m edges. You need to find a path (perh...
app_data_1661
Maxim wants to buy some games at the local game shop. There are $n$ games in the shop, the $i$-th game costs $c_i$. Maxim has a wallet which can be represented as an array of integers. His wallet contains $m$ bills, the $j$-th bill has value $a_j$. Games in the shop are ordered from left to right, Maxim tries to buy ...
app_data_1662
Sereja loves integer sequences very much. He especially likes stairs. Sequence a_1, a_2, ..., a_{|}a| (|a| is the length of the sequence) is stairs if there is such index i (1 ≤ i ≤ |a|), that the following condition is met: a_1 < a_2 < ... < a_{i} - 1 < a_{i} > a_{i} + 1 > ... > a_{|}a| - 1 > a_{|}a|. For example, s...
app_data_1663
Sometimes it is not easy to come to an agreement in a bargain. Right now Sasha and Vova can't come to an agreement: Sasha names a price as high as possible, then Vova wants to remove as many digits from the price as possible. In more details, Sasha names some integer price $n$, Vova removes a non-empty substring of (co...
app_data_1664
Let's analyze a program written on some strange programming language. The variables in this language have names consisting of $1$ to $4$ characters, and each character is a lowercase or an uppercase Latin letter, or a digit. There is an extra constraint that the first character should not be a digit. There are four ty...
app_data_1665
You are given a tree consisting of $n$ nodes. You want to write some labels on the tree's edges such that the following conditions hold: Every label is an integer between $0$ and $n-2$ inclusive. All the written labels are distinct. The largest value among $MEX(u,v)$ over all pairs of nodes $(u,v)$ is as small as ...
app_data_1666
Petya and Vasya are tossing a coin. Their friend Valera is appointed as a judge. The game is very simple. First Vasya tosses a coin x times, then Petya tosses a coin y times. If the tossing player gets head, he scores one point. If he gets tail, nobody gets any points. The winner is the player with most points by the e...
app_data_1667
For long time scientists study the behavior of sharks. Sharks, as many other species, alternate short movements in a certain location and long movements between locations. Max is a young biologist. For $n$ days he watched a specific shark, and now he knows the distance the shark traveled in each of the days. All the d...
app_data_1668
A PIN code is a string that consists of exactly $4$ digits. Examples of possible PIN codes: 7013, 0000 and 0990. Please note that the PIN code can begin with any digit, even with 0. Polycarp has $n$ ($2 \le n \le 10$) bank cards, the PIN code of the $i$-th card is $p_i$. Polycarp has recently read a recommendation th...
app_data_1669
International Coding Procedures Company (ICPC) writes all its code in Jedi Script (JS) programming language. JS does not get compiled, but is delivered for execution in its source form. Sources contain comments, extra whitespace (including trailing and leading spaces), and other non-essential features that make them qu...
app_data_1670
Vasya has started watching football games. He has learned that for some fouls the players receive yellow cards, and for some fouls they receive red cards. A player who receives the second yellow card automatically receives a red card. Vasya is watching a recorded football match now and makes notes of all the fouls tha...
app_data_1671
In the school computer room there are n servers which are responsible for processing several computing tasks. You know the number of scheduled tasks for each server: there are m_{i} tasks assigned to the i-th server. In order to balance the load for each server, you want to reassign some tasks to make the difference b...
app_data_1672
Mad scientist Mike entertains himself by arranging rows of dominoes. He doesn't need dominoes, though: he uses rectangular magnets instead. Each magnet has two poles, positive (a "plus") and negative (a "minus"). If two magnets are put together at a close distance, then the like poles will repel each other and the oppo...
app_data_1673
Let's call beauty of an array $b_1, b_2, \ldots, b_n$ ($n > 1$)  — $\min\limits_{1 \leq i < j \leq n} |b_i - b_j|$. You're given an array $a_1, a_2, \ldots a_n$ and a number $k$. Calculate the sum of beauty over all subsequences of the array of length exactly $k$. As this number can be very large, output it modulo $99...
app_data_1674
You are playing a new famous fighting game: Kortal Mombat XII. You have to perform a brutality on your opponent's character. You are playing the game on the new generation console so your gamepad have $26$ buttons. Each button has a single lowercase Latin letter from 'a' to 'z' written on it. All the letters on button...
app_data_1675
Consider a football tournament where n teams participate. Each team has two football kits: for home games, and for away games. The kit for home games of the i-th team has color x_{i} and the kit for away games of this team has color y_{i} (x_{i} ≠ y_{i}). In the tournament, each team plays exactly one home game and ex...
app_data_1676
In this problem you have to simulate the workflow of one-thread server. There are n queries to process, the i-th will be received at moment t_{i} and needs to be processed for d_{i} units of time. All t_{i} are guaranteed to be distinct. When a query appears server may react in three possible ways: If server is free...
app_data_1677
Gena loves sequences of numbers. Recently, he has discovered a new type of sequences which he called an almost arithmetical progression. A sequence is an almost arithmetical progression, if its elements can be represented as: a_1 = p, where p is some integer; a_{i} = a_{i} - 1 + ( - 1)^{i} + 1·q (i > 1), where q is s...
app_data_1678
Petya has an array $a$ consisting of $n$ integers. He has learned partial sums recently, and now he can calculate the sum of elements on any segment of the array really fast. The segment is a non-empty sequence of elements standing one next to another in the array. Now he wonders what is the number of segments in his ...
app_data_1679
Polycarp has just invented a new binary protocol for data transmission. He is encoding positive integer decimal number to binary string using following algorithm: Each digit is represented with number of '1' characters equal to the value of that digit (for 0 it is zero ones). Digits are written one by one in order ...
app_data_1680
Vasya has the sequence consisting of n integers. Vasya consider the pair of integers x and y k-interesting, if their binary representation differs from each other exactly in k bits. For example, if k = 2, the pair of integers x = 5 and y = 3 is k-interesting, because their binary representation x=101 and y=011 differs ...
app_data_1681
Once little Vasya read an article in a magazine on how to make beautiful handmade garland from colored paper. Vasya immediately went to the store and bought n colored sheets of paper, the area of each sheet is 1 square meter. The garland must consist of exactly m pieces of colored paper of arbitrary area, each piece s...
app_data_1682
Igor found out discounts in a shop and decided to buy n items. Discounts at the store will last for a week and Igor knows about each item that its price now is a_{i}, and after a week of discounts its price will be b_{i}. Not all of sellers are honest, so now some products could be more expensive than after a week of ...
app_data_1683
This problem differs from the previous one only in the absence of the constraint on the equal length of all numbers $a_1, a_2, \dots, a_n$. A team of SIS students is going to make a trip on a submarine. Their target is an ancient treasure in a sunken ship lying on the bottom of the Great Rybinsk sea. Unfortunately, th...
app_data_1684
Inaka has a disc, the circumference of which is $n$ units. The circumference is equally divided by $n$ points numbered clockwise from $1$ to $n$, such that points $i$ and $i + 1$ ($1 \leq i < n$) are adjacent, and so are points $n$ and $1$. There are $m$ straight segments on the disc, the endpoints of which are all am...
app_data_1685
T is a complete binary tree consisting of n vertices. It means that exactly one vertex is a root, and each vertex is either a leaf (and doesn't have children) or an inner node (and has exactly two children). All leaves of a complete binary tree have the same depth (distance from the root). So n is a number such that n ...
app_data_1686
The problem uses a simplified TCP/IP address model, please make sure you've read the statement attentively. Polycarpus has found a job, he is a system administrator. One day he came across n IP addresses. Each IP address is a 32 bit number, represented as a group of four 8-bit numbers (without leading zeroes), separat...
app_data_1687
Ksusha is a beginner coder. Today she starts studying arrays. She has array a_1, a_2, ..., a_{n}, consisting of n positive integers. Her university teacher gave her a task. Find such number in the array, that all array elements are divisible by it. Help her and find the number! -----Input----- The first line contai...
app_data_1688
Your favorite music streaming platform has formed a perfectly balanced playlist exclusively for you. The playlist consists of $n$ tracks numbered from $1$ to $n$. The playlist is automatic and cyclic: whenever track $i$ finishes playing, track $i+1$ starts playing automatically; after track $n$ goes track $1$. For eac...
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ZS the Coder and Chris the Baboon are travelling to Udayland! To get there, they have to get on the special IOI bus. The IOI bus has n rows of seats. There are 4 seats in each row, and the seats are separated into pairs by a walkway. When ZS and Chris came, some places in the bus was already occupied. ZS and Chris are...
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You went to the store, selling $n$ types of chocolates. There are $a_i$ chocolates of type $i$ in stock. You have unlimited amount of cash (so you are not restricted by any prices) and want to buy as many chocolates as possible. However if you buy $x_i$ chocolates of type $i$ (clearly, $0 \le x_i \le a_i$), then for a...
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PolandBall has such a convex polygon with n veritces that no three of its diagonals intersect at the same point. PolandBall decided to improve it and draw some red segments. He chose a number k such that gcd(n, k) = 1. Vertices of the polygon are numbered from 1 to n in a clockwise way. PolandBall repeats the followi...
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Max wants to buy a new skateboard. He has calculated the amount of money that is needed to buy a new skateboard. He left a calculator on the floor and went to ask some money from his parents. Meanwhile his little brother Yusuf came and started to press the keys randomly. Unfortunately Max has forgotten the number which...
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This is a harder version of the problem. In this version $n \le 500\,000$ The outskirts of the capital are being actively built up in Berland. The company "Kernel Panic" manages the construction of a residential complex of skyscrapers in New Berlskva. All skyscrapers are built along the highway. It is known that the c...
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Xenia the vigorous detective faced n (n ≥ 2) foreign spies lined up in a row. We'll consider the spies numbered from 1 to n from left to right. Spy s has an important note. He has to pass the note to spy f. Xenia interrogates the spies in several steps. During one step the spy keeping the important note can pass the ...
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A class of students wrote a multiple-choice test. There are $n$ students in the class. The test had $m$ questions, each of them had $5$ possible answers (A, B, C, D or E). There is exactly one correct answer for each question. The correct answer for question $i$ worth $a_i$ points. Incorrect answers are graded with ze...
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The capital of Berland looks like a rectangle of size n × m of the square blocks of same size. Fire! It is known that k + 1 blocks got caught on fire (k + 1 ≤ n·m). Those blocks are centers of ignition. Moreover positions of k of these centers are known and one of these stays unknown. All k + 1 positions are distinct...
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Fox Ciel is playing a mobile puzzle game called "Two Dots". The basic levels are played on a board of size n × m cells, like this: [Image] Each cell contains a dot that has some color. We will use different uppercase Latin characters to express different colors. The key of this game is to find a cycle that contain d...
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One way to create a task is to learn from life. You can choose some experience in real life, formalize it and then you will get a new task. Let's think about a scene in real life: there are lots of people waiting in front of the elevator, each person wants to go to a certain floor. We can formalize it in the following...
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While resting on the ship after the "Russian Code Cup" a boy named Misha invented an interesting game. He promised to give his quadrocopter to whoever will be the first one to make a rectangular table of size n × m, consisting of positive integers such that the sum of the squares of numbers for each row and each column...