input stringlengths 20 127k | target stringlengths 20 119k | problem_id stringlengths 6 6 |
|---|---|---|
N = int(eval(input()))
light_rule = {n:int(eval(input()))-1 for n in range(N)}
light = ["1"]+["0"]*(N-1)
target = ["0"]+["1"]+["0"]*(N-2)
searched = {"".join(light):1}
flag = 0
num = 0
bottun = 0
for _ in range(N):
if light == target:
flag = 1
break
num += 1
# print(bottun, ... | N = int(eval(input()))
light_rule = {n:int(eval(input()))-1 for n in range(N)}
light = ["1"]+["0"]*(N-1)
flag = 0
num = 0
bottun = 0
for _ in range(N):
if light[1] == "1":
flag = 1
break
num += 1
# print(bottun, light_rule[bottun])
light[bottun] = "0"
light[light_rul... | p03680 |
# ABC 65, B - trained
n = int(eval(input()))
A = [int(eval(input())) for i in range(n)]
went = []
now = 1
for i in range(n):
if now in went:
print((-1))
break
if now == 2:
print(i)
break
went.append(now)
now = A[now-1]
| # ABC 65, B - trained
n = int(eval(input()))
A = [int(eval(input())) for i in range(n)]
now = 1
went = set()
for i in range(n):
if now == 2:
print(i)
break
if now in went:
print((-1))
break
went.add(now)
now = A[now-1]
| p03680 |
n = int(eval(input()))
a = [int(eval(input())) for i in range(n)]
x = 1
y = []
while x not in y and x != 2:
y += [x]
x = a[x-1]
if x == 2:
print((len(y)))
else:
print((-1))
| n = int(eval(input()))
a = [int(eval(input())) for i in range(n)]
x = 1
y = [0] * n
while y[x-1] != 2 and x != 2:
y[x-1] += 1
x = a[x-1]
if x == 2:
print((y.count(1)))
else:
print((-1))
| p03680 |
n = int(eval(input()))
a = [int(eval(input())) for i in range(n)]
x = 1
y = [0] * n
while y[x-1] != 2 and x != 2:
y[x-1] += 1
x = a[x-1]
if x == 2:
print((y.count(1)))
else:
print((-1))
| n = int(eval(input()))
a = [int(eval(input())) for i in range(n)]
x = 1
i = 0
while i < n and x != 2:
x = a[x-1]
i += 1
if x == 2:
print(i)
else:
print((-1))
| p03680 |
n = int(eval(input()))
a = [int(eval(input())) for _ in range(n)]
if 2 not in a:
print((-1))
quit()
else:
t = a.index(2)
s = 1
count = 0
while count <= 10**6:
s = a[s-1]
count += 1
if s == 2:
print(count)
quit()
print((-1)) | n = int(eval(input()))
a = [int(eval(input())) for _ in range(n)]
if 2 not in a:
print((-1))
quit()
else:
s = 1
count = 0
while count <= n:
s = a[s-1]
count += 1
if s == 2:
print(count)
quit()
print((-1)) | p03680 |
n = int(eval(input()))
a = [int(eval(input())) for i in range(n)]
s = [1,a[0]] #shone buttons
while True: #unitl 2 appears in s or a loop generates
if s[-1] == 2: #if 2 appears
break
if len(set(s)) != len(s): #if a loop generates: mathematical induction
break
s += [a[s[-1]-1]]
# p... | n = int(eval(input()))
a = [int(eval(input()))-1 for i in range(n)]
#ボタンを押す=listから値を取得して-1にする
#取得した値=光っているボタンの番号
#光っているボタンの番号が1ならbreak
#取得した値が-1なら2を通らずループしてしまっている
sb = 0
ans = 0
while True:
if sb == 1:
flag = True
break
elif sb == -1:
flag = False
break
tmp = a... | p03680 |
n=int(eval(input()))
a=[]
for i in range(n):
b=int(eval(input()))
a.append(b)
count=1
c=a[0]
while c != 2:
c=a[c-1]
if a[c-1] == b:
print((-1))
exit()
b=c
count +=1
print(count) | n=int(eval(input()))
a=[int(eval(input())) for i in range(n)]
count=1
for i in range(n):
if count == 2:
print(i)
exit()
count=a[count-1]
print((-1)) | p03680 |
N=int(eval(input()))
alist=[0]
for i in range(N):
alist.append(int(eval(input())))
#print(alist)
answer=0
pos=1
set_pos=set()
while True:
if pos==2:
print(answer)
break
else:
pos=alist[pos]
answer+=1
if pos in set_pos:
print((-1))
break
else:
set_pos.add(po... | N=int(eval(input()))
alist=[0]
for i in range(N):
alist.append(int(eval(input())))
#print(alist)
answer=0
pos=1
while True:
if answer>N:
print((-1))
break
elif pos==2:
print(answer)
break
else:
pos=alist[pos]
answer+=1 | p03680 |
import sys
N = int(eval(input()))
a = []
for i in range(N):
a.append(int(eval(input())))
count = 0
saw = []
now = 1
while now not in saw:
count += 1
saw.append(now)
now = a[now - 1]
if now == 2:
print(count)
sys.exit()
print((-1))
| import sys
N = int(eval(input()))
a = []
for i in range(N):
a.append(int(eval(input())))
count = 0
now = 1
while count < N:
count += 1
now = a[now - 1]
if now == 2:
print(count)
sys.exit()
print((-1))
| p03680 |
import sys
from collections import deque
n = int(eval(input()))
a = [0] + [int(sys.stdin.readline()) for _ in range(n)]
pushed = deque([1])
button = 1
for _ in range(n):
if a[button] in pushed:
print((-1))
break
pushed.append(a[button])
button = a[button]
if button == 2... | import sys
n = int(eval(input()))
a = [0] + [int(sys.stdin.readline()) for _ in range(n)]
button = 1
count = 0
for _ in range(n):
if button == 2:
print(count)
break
button = a[button]
count += 1
if count == n:
print((-1)) | p03680 |
import sys
n = int(eval(input()))
a = [0] + [int(sys.stdin.readline()) for _ in range(n)]
button = 1
count = 0
for _ in range(n):
if button == 2:
print(count)
break
button = a[button]
count += 1
if count == n:
print((-1)) | import sys
n = int(eval(input()))
a = [0] + [int(sys.stdin.readline()) for _ in range(n)]
button = 1
count = 0
for _ in range(n):
if button == 2:
print(count)
break
button = a[button]
count += 1
else:
print((-1)) | p03680 |
import sys
n = int(eval(input()))
a = [0] + [int(sys.stdin.readline()) for _ in range(n)]
button = 1
for i in range(n):
if button == 2:
print(i)
break
button = a[button]
else:
print((-1)) | import sys
n = list(map(int, sys.stdin))
button = 1
for i in range(n[0]):
if button == 2:
print(i)
break
button = n[button]
else:
print((-1)) | p03680 |
N=int(eval(input()))
a=[]
for i in range(N):
a.append(int(eval(input())))
flag=True
step=[]
pivot=0
for i in range(N):
step.append(pivot)
if a[pivot]==2:
break
pivot=a[pivot]-1
if pivot in step:
flag=False
break
if flag:
print((len(step)))
else:
print((-1)) | N=int(eval(input()))
a=[]
for i in range(N):
a.append(int(eval(input()))-1)
flag=True
step=[]
pivot=0
for i in range(N+1):
step.append(pivot)
if a[pivot]==1:
break
pivot=a[pivot]
if len(step)>N:
print((-1))
else:
print((len(step))) | p03680 |
n=int(eval(input()))
num=[0]
ans=0
count=0
k=1
for i in range(n):
a=int(eval(input()))
num.append(a)
for i in range(n+1):
k=num[k]
count+=1
if k==2:
ans=1
break
if ans==1:
print(count)
else:
print("-1") | #1
n = int(eval(input()))
a = [0]
for i in range(n):
a.append(int(eval(input())))
cnt = 0
b = 1
ans = 0
for j in range(n+1):
cnt += 1
b = a[b]
if b == 2:
ans = 1
break
if ans == 1:
print(cnt)
else:
print("-1")
| p03680 |
N = int(eval(input()))
al = [[] for _ in range(N+1)]
for i in range(1,N+1):
al[i] = int(eval(input()))
#print(al)
#初期値
n = 1
cnt = 1
visited = [0 for _ in range(N+1)]
visited[1] = 1
while al[n] != 2:
cnt += 1
n = al[n]
if visited[n] == 1:
print((-1))
exit()
print(cnt)
... | N = int(eval(input()))
al = [[] for _ in range(N+1)]
for i in range(1,N+1):
al[i] = int(eval(input()))
#print(al)
#初期値
n = 1
cnt = 1
visited = [0 for _ in range(N+1)]
visited[1] = 1
while al[n] != 2:
cnt += 1
n = al[n]
if visited[n] == 1:
print((-1))
exit()
else:
... | p03680 |
n = int(eval(input()))
a = [int(eval(input())) for i in range(n)]
ans = False
used = set()
i = 1
count = 0
while ans == False:
count += 1
if a[i-1] == 2:
ans = True
elif i-1 in used:
break
else:
used.add(i-1)
i = a[i-1]
if ans == True:
print(count)
el... | n = int(eval(input()))
a = [int(eval(input())) for i in range(n)]
count = 0
i = 0
ans = False
while count < n:
count += 1
if a[i] == 2:
ans = True
break
else:
i = a[i] - 1
if ans == True:
print(count)
else:
print("-1") | p03680 |
n = int(eval(input()))
rec = {}
for i in range(n):
a = int(eval(input()))
rec[i + 1] = a
i = 1
rec2 = [1]
num = 0
while i != 2 and num < n:
i = rec[i]
if i not in rec2:
rec2.append(i)
num += 1
else:
num = -1
break
if num == n:
print((-1))
el... | n = int(eval(input()))
rec = {}
for i in range(n):
a = int(eval(input()))
rec[i + 1] = a
i = 1
rec2 = [1]
num = 0
while i != 2 and num < n:
i = rec[i]
num += 1
if num == n:
print((-1))
else:
print(num) | p03680 |
n = int(eval(input()))
rec = {}
for i in range(n):
a = int(eval(input()))
rec[i + 1] = a
i = 1
rec2 = [1]
num = 0
while i != 2 and num < n:
i = rec[i]
num += 1
if num == n:
print((-1))
else:
print(num) | N = int(eval(input()))
A = []
for i in range(N):
a = int(eval(input()))
A.append(a - 1)
i = 0
k = 0
s = set()
flag = True
while i != 1:
if i in s:
flag = False
break
s.add(i)
i = A[i]
k += 1
if flag:
print(k)
else:
print((-1))
| p03680 |
n=int(eval(input()))
a=[int(eval(input())) for _ in range(n)]
b=[1]
buf=1
if 2 not in a:
print((-1))
else:
while True:
a_buf=a[buf-1]
if a_buf==2:
print((len(b)))
break
elif a_buf in b:
print((-1))
break
b.append(a_bu... | n=int(eval(input()))
a=[int(eval(input())) for _ in range(n)]
b=[1]
buf=1
count=0
if 2 not in a:
print((-1))
else:
while count<n:
a_buf=a[buf-1]
#print("buf,a[buf-1],b=",buf,a[buf-1],b)
if a_buf==2:
#print("check_2")
print((len(b)))
break... | p03680 |
n = int(input())
edges = [[0 for _ in range(n)] for _ in range(n)]
mem = [[0 for _ in range(n)] for _ in range(n)]
dist = []
for i in range(n):
edges[i][int(input())-1] = 1
def has_edge(edges, v, t, d):
targets = [i for i, e in enumerate(edges[v]) if e != 0]
for target in targets:
if me... | n = int(eval(input()))
edges = {i: int(eval(input()))-1 for i in range(n)}
def push_buttom(v, goal):
for i in range(n):
v = edges[v]
if v == goal:
return i+1
return -1
print((push_buttom(0, 1)))
| p03680 |
N = int(eval(input()))
a = [int(eval(input())) for _ in range(N)]
b = [-1] * N
botan = a[0]
cnt = 0
for i in range(N):
if botan == 2:
print((cnt + 1))
exit()
cnt += 1
botan = a[botan - 1]
print((-1))
| from sys import stdin
input = stdin.readline
N = int(eval(input()))
a = [int(eval(input())) for _ in range(N)]
b = [-1] * N
botan = a[0]
cnt = 0
for i in range(N):
if botan == 2:
print((cnt + 1))
exit()
cnt += 1
botan = a[botan - 1]
print((-1))
| p03680 |
n = int(eval(input()))
btn_list = {i:int(eval(input())) for i in range(1,n+1)}
count = 0
btn = 1
while True:
if btn == 2:
print(count)
break
elif btn == 1 and count != 0:
print((-1))
break
else:
count += 1
btn = btn_list[btn] | n = int(eval(input()))
btn_list = {i:int(eval(input())) for i in range(1,n+1)}
count = 1
right = btn_list[1]
while True:
if right == 2:
print(count)
break
elif count == n:
print((-1))
break
else:
count += 1
right = btn_list[right] | p03680 |
n = int(eval(input()))
L = sum([list(map(int, input().split())) for i in range(n)], [])
next = 0
for i in range(len(L)):
if L[next] == 2:
print((i+1))
quit()
next = L[next]-1
print((-1)) | n = int(eval(input()))
a = [int(eval(input())) for _ in range(n)]
cur = 1
cnt = 0
while True:
if cur == 2:
print(cnt)
exit()
elif cnt > n:
print((-1))
exit()
else:
cur = a[cur - 1]
cnt += 1 | p03680 |
n = int(eval(input()))
L = sum([list(map(int, input().split())) for i in range(n)], [])
next = 1
count = 0
while True:
if next == 2:
print(count)
exit()
elif count > n:
print((-1))
exit()
else:
next = L[next-1]
count += 1 | n = int(eval(input()))
L = [int(eval(input())) for _ in range(n)]
next = 1
count = 0
while True:
if next == 2:
print(count)
exit()
elif count > n:
print((-1))
exit()
else:
next = L[next-1]
count += 1 | p03680 |
n = int(eval(input()))
L = [int(eval(input())) for _ in range(n)]
count = 0
next = 0
for i in range(len(L)):
if L[next] == 2:
print((count+1))
quit()
next = L[next]-1
count += 1
print((-1)) | n = int(eval(input()))
L = [int(eval(input())) for _ in range(n)]
next = 1
for i in range(n):
if next == 2:
print(i)
quit()
next = L[next-1]
print((-1)) | p03680 |
n=int(eval(input()))
a=[]
for _ in range(n):
a.append(int(eval(input())))
t=0
for i in range(1,n+1):
t=a[t]-1
if t==1:
print(i)
break
else:
print((-1)) | n=int(eval(input()))
a=[int(eval(input()))for _ in range(n)]
b=0
for i in range(1,n+1):
b=a[b]-1
if b==1:
print(i)
exit()
else:
print((-1)) | p03680 |
n = int(eval(input()))
l = [0 for _ in range(n)]
already = []
next = 1
c = 0
for i in range(n):
a = int(eval(input()))
l[i] = a
while c <= n:
next = l[next-1]
c += 1
if next == 2:
print(c)
break
elif next in already:
print((-1))
break
already.append(next) | n = int(eval(input()))
l = [0 for _ in range(n)]
already = set()
next = 1
c = 0
for i in range(n):
a = int(eval(input()))
l[i] = a
while c <= n:
next = l[next-1]
c += 1
if next == 2:
print(c)
break
elif next in already:
print((-1))
break
already.add(next) | p03680 |
n = int(eval(input()))
a = [int(eval(input())) for _ in range(n)]
A = [0]*n
i = 0
ok = False
cnt = 0
for _ in range(n):
cnt += 1
A[i] = 1
if a[i] == 2:
ok = True
break
i = a[i]-1
if A[i] == 1: break
print((cnt if ok else -1)) | n = int(eval(input()))
a = [0]+[int(eval(input())) for _ in range(n)]
check = [0] * (n+1)
now = 1
cnt = 0
while now != 2:
if check[now] == 1: break
cnt += 1
check[now] = 1
now = a[now]
print((cnt if now == 2 else -1)) | p03680 |
n=int(eval(input()))
s=list(int(eval(input())) for _ in range(n))
push=[0 for _ in range(n)]
index=0
cnt=1
flag=True
while flag:
push[index]+=1
if s[index]==2:
print(cnt)
flag=False
else:
if push.count(2)!=0:
print((-1))
flag=False
e... | n=int(eval(input()))
a=[int(eval(input())) for i in range(n)]
c,s=1,a[0]
while s!=2 and c<n:
c,s=c+1,a[s-1]
print((c if c<n else -1)) | p03680 |
N = int(eval(input()))
a = [int(eval(input())) for i in range(N)]
count = [0]*N
i = 0
while(True):
i = a[i]-1
count[i]+=1
if i == 1:
print((sum(count)))
break
if max(count)==2:
print((-1))
break | N = int(eval(input()))
a = [int(eval(input())) for i in range(N)]
count = [0]*N
i = 0
while(True):
count[i]+=1
i = a[i]-1
if i == 1:
print((sum(count)))
break
if count[i] == 1:
print((-1))
break | p03680 |
#2019/10/16
N, *a = list(map(int, open(0).read().split()))
#print(N, a)
i=0
cnt=1
button=[]
while(True):
#print("i=",i, "a[i]=",a[i])
#print("button=", button)
i=a[i]-1
if i==1:
print(cnt)
break
elif i in button:
print("-1")
break
else:
bu... | #2019/10/16
N, *a = list(map(int, open(0).read().split()))
#print(N, a)
i=0
cnt=0
button=[]
while(True):
#print("i=",i, "a[i]=",a[i])
#print("button=", button)
if i==1:
print(cnt)
break
if cnt >= N:
print("-1")
break
cnt+=1
i=a[i]-1 | p03680 |
import sys
n = int(eval(input()))
ls = [int(eval(input())) for _ in range(n)]
if 2 not in ls:
print((-1))
sys.exit()
i = 1
k = 0
di = []
for j in range(n):
i = ls[i-1]
if i in di:
print((-1))
break
di.append(i)
k += 1
if i == 2:
print(k)
brea... | import sys
n = int(eval(input()))
ls = [int(eval(input())) for _ in range(n)]
if 2 not in ls:
print((-1))
sys.exit()
i = 1
k = 0
for j in range(n):
i = ls[i-1]
k += 1
if i == 2:
print(k)
sys.exit()
print((-1)) | p03680 |
n=int(eval(input()))
a=[int(eval(input())) for i in range(n)]
tmp=[]
i=1
cnt=0
while cnt<=n:
i=a[i-1]
cnt+=1
if i==2:
print(cnt)
break
else:
print((-1)) | n=int(eval(input()))
a=[int(eval(input())) for i in range(n)]
i=1
cnt=0
while cnt<=n:
i=a[i-1]
cnt+=1
if i==2:
print(cnt)
break
else:
print((-1)) | p03680 |
# -*- coding:utf-8 -*-
import sys
nyuryoku = [int(i) for i in sys.stdin]
N = nyuryoku[0]
a_list = nyuryoku[1:]
"""
a_list=[]
for _ in range(N):
a_list.append(int(input()))
"""
cnt_push = 1
button_list = []
cur_but_posi = a_list[0]
while True:
#cur_but_posi = a_list[cur_but_posi - 1]
... | import sys
l = [int(i) - 1 for i in sys.stdin]
N = l[0] + 1
a = l[1:]
done = [False] * N
i = 0
ans = 0
while True:
if done[i] == False:
done[i] = True
ans += 1
if a[i] == 1:
break
i = a[i]
else:
ans = -1
break
print(ans... | p03680 |
n = int(eval(input()))
a = []
for _ in range(n):
a.append(int(eval(input())))
a.insert(0,0)
ans = 0
visited = []
i = 1
while True:
if a[i] == 2:
ans += 1
break
elif not i in visited:
ans += 1
visited.append(i)
i = a[i]
else:
ans = -1
... | n = int(eval(input()))
a = []
for _ in range(n):
a.append(int(eval(input())))
a.insert(0,0)
ans = 0
i = 1
for x in range(n+1):
if a[i] == 2:
ans += 1
break
elif x == n:
ans = -1
break
else:
ans += 1
i = a[i]
print(ans) | p03680 |
# import sys
# input = sys.stdin.readline
N, *a = [int(x) for x in open(0)]
a.insert(0, None)
first = 1
pres = first
count = 0
nex = a[pres] # press the button
count += 1
for i in range(N-1): # operations are at most N-1 times.
if nex == 2: break
prev = pres
pres = nex
nex = a[pres] # ... | import sys
n, *b = list(map(int, sys.stdin.read().split()))
def main():
on = 1
lightened = set([1])
for i in range(1, n):
on = b[on-1]
if on == 2:
return i
if on in lightened:
return -1
lightened.add(on)
if __name__ == '__main__':
... | p03680 |
n = int(eval(input()))
a = [int(eval(input())) for _ in range(n)]
now = 1
ans = 0
while True:
now = a[now-1]
ans += 1
if (now==2):
print(ans)
break
elif (now==1):
print((-1))
break
| n = int(eval(input()))
a = [int(eval(input())) for _ in range(n)]
now = 1
ans = 0
while True:
now = a[now-1]
ans += 1
if (now==2):
print(ans)
break
elif (now==1):
print((-1))
break
elif (ans>len(a)):
print((-1))
break
| p03680 |
N = int(eval(input()))
a = []
for _ in range(N):
a += [int(eval(input()))]
lst = [0] * N
flag = True
i = 0
count = 0
while flag:
if lst[i] == 1:
print((-1))
exit()
elif a[i] == 2:
print((count + 1))
exit()
else:
lst[i] = 1
i = a[i] -... | import sys
input = sys.stdin.readline
N = int(eval(input()))
A = [int(eval(input())) for _ in range(N)]
check = [True] * (N + 1)
count = 0
tmp = 1
while check[tmp]:
count += 1
check[tmp] = False
if A[tmp - 1] == 2:
print (count)
exit()
tmp = A[tmp - 1]
print((-1)) | p03680 |
import sys
sys.setrecursionlimit(500000)
N=int(eval(input()))
A=[int(eval(input()))-1 for _ in range(N)]
result=[]
app=result.append
def next(k):
newlight=A[k]
if k==1:
return(1)
elif k in result:
return(0)
else:
app(k)
return(next(newlight))
if not next(0):
print((-1))
else:print((len(res... | import sys
sys.setrecursionlimit(500000)
N=int(eval(input()))
A=[int(eval(input()))-1 for _ in range(N)]
result=[False]*N
def next(k):
newlight=A[k]
if k==1:
return(1)
elif result[k]:
return(0)
else:
result[k]=True
return(next(newlight))
if not next(0):
print((-1))
else:print((sum(result))) | p03680 |
n = int(eval(input()))
light = 1
count = 0
a = []
his = []
for i in range(n):
a.append(int(eval(input())))
while light not in his:
his.append(light)
light = a[light-1]
count += 1
if light == 2:
print(count)
quit()
print((-1))
| n = int(eval(input()))
light = 1
count = 0
a = []
for i in range(n):
a.append(int(eval(input())))
while count < n:
light = a[light-1]
count += 1
if light == 2:
print(count)
quit()
print((-1))
| p03680 |
N = int(eval(input()))
a = [int(eval(input()))-1 for i in range(N)]
hist = []
next_i = 0
ans = 0
for i in range(N):
ans += 1
hist.append(next_i)
next_i = a[next_i]
if next_i == 1:
break
elif next_i in hist:
ans = -1
break
print(ans) | N = int(eval(input()))
a = [int(eval(input()))-1 for i in range(N)]
hist = set()
next_i = 0
ans = 0
for i in range(N):
ans += 1
hist.add(next_i)
next_i = a[next_i]
if next_i == 1:
break
elif next_i in hist:
ans = -1
break
print(ans) | p03680 |
n = int(eval(input()))
buttons = [0] * 10**5
for i in range(n):
buttons[i] = int(eval(input()))
next = 1
i = 0
while next != 2:
i += 1
next = buttons[next-1]
if next == 2:
print(i)
exit()
if i >= 10**5:
print((-1))
break
| n = int(eval(input()))
buttons = []
for i in range(n):
buttons.append(int(eval(input())))
next = 1
i = 0
while i <= 10**5:
i += 1
next = buttons[next-1]
if next == 2:
print(i)
exit()
print((-1))
| p03680 |
n = int(eval(input()))
buttons = [0] * 10**5
for i in range(n):
buttons[i] = int(eval(input()))
next = 1
i = 0
while i <= 10**5:
i += 1
next = buttons[next-1]
if next == 2:
print(i)
exit()
print((-1))
| n = int(eval(input()))
A = [int(eval(input())) for _ in range(n)]
next = 0
ans = 0
while ans <= n:
ans += 1
if A[next] == 2:
print(ans)
exit()
next = A[next]-1
print((-1))
| p03680 |
N = int(eval(input()))
A = [int(eval(input())) for _ in range(N)]
check = [True for _ in range(N)]
ai = 1
count = 1
while check[ai-1]:
if A[ai-1] == 2:
print(count)
exit()
check[ai-1] = False
ai = A[ai-1]
count += 1
print((-1))
| N = int(eval(input()))
A = [int(eval(input())) for _ in range(N)]
order = A[0]
for i in range(1,N):
if order == 2:
print(i)
exit()
order = A[order-1]
print((-1)) | p03680 |
import sys
N = int(eval(input()))
button = [0]*N
for i in range(N):
button[i] = int(eval(input()))-1
course = []
count, now = 0, 0
while not now in course:
course.append(now)
now = button[now]
count += 1
if now == 1:
print(count)
sys.exit()
print((-1))
| import sys
N = int(eval(input()))
button = [0]*N
for i in range(N):
button[i] = int(eval(input()))-1
count, now = 0, 0
while count <= N:
now = button[now]
count += 1
if now == 1:
print(count)
sys.exit()
print((-1))
| p03680 |
from collections import defaultdict, deque
N = int(eval(input()))
d = defaultdict(int)
for i in range(N):
d[i+1] = int(eval(input()))
#print(d)
q = []
q.append(1)
point = 1
count = 1
while True:
if d[point] in q:
print((-1))
break
if d[point] == 2:
print(co... | from collections import defaultdict, deque
import sys
N = int(eval(input()))
d = defaultdict(int)
for i in range(N):
d[i+1] = int(eval(input()))
#print(d)
q = deque()
q.append(1)
point = 1
count = 1
while N > 0:
if d[point] == 2:
print(count)
sys.exit()
q.a... | p03680 |
N = int(eval(input()))
A = [int(eval(input())) for i in range(N)]
cnt = 1
if 2 not in A:
print((-1))
exit()
a = A[0]
while a != 2:
if a == 1:
print((-1))
exit()
a = A[a-1]
cnt += 1
if a == 1:
print((-1))
exit()
print(cnt)
| n = int(eval(input()))
a = [int(eval(input())) for i in range(n)]
cnt = 0
if 2 not in a:
print((-1))
exit()
x = 1
for i in range(n-1):
x = a[x-1]
cnt += 1
if x == 2:
print(cnt)
exit()
print((-1)) | p03680 |
n = int(eval(input()))
a = []
for i in range(n):
a.append(int(eval(input())))
log_l = [0]
i = 0
count = 0
flag = False
while i != 1:
i = a[i]-1
count +=1
if i in log_l: break
else: log_l.append(i)
if i == 1:
flag = True
break
if flag: print(count)
else: print((-... | n = int(eval(input()))
a = []
for i in range(n):
a.append(int(eval(input())))
i = 0
j = 0
count = -1
while i < n:
j = a[j]-1
i += 1
if j == 1:
count = i
break
print(count) | p03680 |
N = int(eval(input()))
A = [int(eval(input())) for i in range(N)]
G = [1]
for i in range(N):
G.append(A[G[-1]-1])
ans = 0
for i in range(N+1):
if G[i]==2:
break
ans += 1
else:
ans = -1
print(ans) | N = int(eval(input()))
A = [int(eval(input())) for i in range(N)]
G = [1]
for i in range(N):
G.append(A[G[-1]-1])
ans = 0
for i in G:
if i==2:
break
ans += 1
else:
ans = -1
print(ans) | p03680 |
N=int(eval(input()))
a = []
for i in range(N):
a.append(int(eval(input())))
# a=[0]*N
# for i in range(N):
# a[i]=int(input())
count=0
#loopの定義→同じインデックスを使用したらloop判定
#in の処理を爆速で実行するためにsetを使用する
#loop=[]
loop=set()
tmp=1
while True:
tmp=a[tmp-1]
count+=1
if tmp==2:
print(count)... | N=int(eval(input()))
#複数行の入力を高速化
#a=[0]*N
#for i in range(N):
# a[i]=int(input())
import sys
a=[int(i) for i in sys.stdin]
count=0
#loopの定義→同じインデックスを使用したらloop判定
#in の処理を爆速で実行するためにsetを使用する
#loop=[]
loop=set()
tmp=1
while True:
tmp=a[tmp-1]
count+=1
if tmp==2:
print(count)
exit()
... | p03680 |
N = int(eval(input()))
a = [""]
for i in range(N):
a.append(int(eval(input())))
button = 1
i = 0
while True:
if button == 2:
print(i)
break
if i > N:
print((-1))
break
button = a[button]
i += 1
| N = int(eval(input()))
a = [""]
for i in range(N):
a.append(int(eval(input())))
ai = 1
for i in range(N):
if ai == 2:
print(i)
exit()
ai = a[ai]
else:
print((-1))
| p03680 |
from sys import stdin
def main() -> int:
n = next_int()
a = [next_int() for _ in range(n)]
j = 1
dic = dict()
for i in range(n):
dic[j] = True
j = a[j - 1]
if j in dic:
break
if j == 2:
print((i + 1))
return 0
... | from sys import stdin
def main() -> int:
n = next_int()
a = [next_int() for _ in range(n)]
j = 1
for i in range(n):
j = a[j - 1]
if j == 2:
print((i + 1))
return 0
print((-1))
return 0
def next_int() -> int:
return int(next_s... | p03680 |
N = int(eval(input()))
a = {}
for i in range(N):
a[i + 1] = int(eval(input()))
i = 1
before_i = None
cnt = 0
while True:
next_i = a[i]
cnt += 1
if next_i in [1, i, before_i]:
print((-1))
break
elif next_i == 2:
print(cnt)
break
before_i = i
... | N = int(eval(input()))
a = {}
for i in range(N):
a[i + 1] = int(eval(input()))
i = 1
cnt = 0
while True:
next_i = a[i]
cnt += 1
if next_i < 1:
print((-1))
break
elif next_i == 2:
print(cnt)
break
a[i] = 0
i = next_i | p03680 |
n = int(eval(input()))
a_list = [0]
for _ in range(n):
a_list.append(int(eval(input())))
counter = 0
current_number = 1
already_pushed_list = []
while(True):
counter += 1
already_pushed_list.append(current_number)
current_number = a_list[current_number]
if current_number in already_push... | n = int(eval(input()))
a_list = [0]
for _ in range(n):
a_list.append(int(eval(input())))
counter = 0
current_number = 1
already_pushed_list = set()
while(True):
counter += 1
already_pushed_list.add(current_number)
current_number = a_list[current_number]
if current_number in already_push... | p03680 |
N = int(eval(input()))
A = [int(eval(input())) for _ in range(N)]
now = 0
count = 0
while True:
if now == 0 and count != 0:
print((-1))
break
if now == 1:
print(count)
break
now = A[now] - 1
count += 1
| N = int(eval(input()))
A = [int(eval(input())) for _ in range(N)]
now = 0
count = 0
while True:
if count >= N:
print((-1))
break
if now == 1:
print(count)
break
now = A[now] - 1
count += 1 | p03680 |
N = int(eval(input()))
a = [int(eval(input()))-1 for i in range(N)]
ans = 0
index = 0
b = [False]*N
b[0] = True
while index!=1:
index = a[index]
if b[index]:
ans = -1
break
ans += 1
print(ans) | N = int(eval(input()))
a = [int(eval(input()))-1 for i in range(N)]
cnt = 0
index = 0
while True:
if index == 1:
print(cnt)
break
elif cnt>N:
print((-1))
break
index = a[index]
cnt += 1 | p03680 |
n = int(eval(input()))
a = []
for i in range(n):
a.append(int(eval(input())) - 1)
# if not 1 in a:
# print(-1)
# hst = []
btn = 0
cnt = 0
while cnt <= 10**7:
# hst.append(btn)
btn = a[btn]
cnt += 1
if btn == 1:
print(cnt)
exit()
print((-1)) | n = int(eval(input()))
a = []
for i in range(n):
a.append(int(eval(input())) - 1)
hst = [0] * n
btn = 0
cnt = 0
while hst[btn] != 1:
hst[btn] = 1
btn = a[btn]
cnt += 1
if btn == 1:
print(cnt)
exit()
print((-1)) | p03680 |
n = int(eval(input()))
a = list(int(eval(input())) for i in range(n))
t = []
o = 1
while o != 2:
if o in t:
print((-1))
exit(0)
t.append(o)
o = a[o-1]
print((len(t))) | n = int(eval(input()))
a = list(int(eval(input())) for i in range(n))
t = []
o = 1
while o != 2:
if len(t) > n:
print((-1))
exit(0)
t.append(o)
o = a[o-1]
print((len(t))) | p03680 |
N = int(eval(input()))
l = []
istwo = False
for i in range(N):
a = int(eval(input()))
if a == 2 and i != 1: istwo = True
l.append(a-1)
flag = [0]*N
flag[0] = 1
flag[1] = 2
cnt = 0
cur_b = 0
while istwo:
cnt += 1
next_b = l[cur_b]
if flag[next_b] == 1:
print((-1))
... | N = int(eval(input()))
l = [(int(eval(input()))-1) for _ in range(N)]
flag = [0]*N
flag[0] = 1
flag[1] = 2
cnt = 0
cur_b = 0
for i in range(N):
cnt += 1
next_b = l[cur_b]
if flag[next_b] == 1:
print((-1))
break
elif flag[next_b] == 2:
print(cnt)
break
... | p03680 |
N = int(eval(input()))
a = [int(eval(input())) for i in range(N)]
tmp = 0
count = 1
tmp = a[0]
while tmp != 2 and tmp != 1:
count += 1
tmp = a[tmp-1]
if tmp == 2:
print(count)
else:
print((-1)) | N = int(eval(input()))
a = [int(eval(input()))-1 for i in range(N)]
owari = [0]*N
tmp = 0
count = 0
while owari[tmp] == 0 and tmp != 1:
count += 1
owari[tmp]=1
tmp = a[tmp]
if tmp == 1:
print(count)
else:
print((-1)) | p03680 |
n = int(eval(input()))
botan = [int(eval(input())) for i in range(n)]
light = 1 # 1番目のボタンが初め光ってる
count = 1
exi = [1]
if 2 in botan:
while True:
light = botan[light - 1]
if light in exi:
print((-1))
exit()
exi.append(light)
if 2 in exi:
... | n = int(eval(input()))
botan = [int(eval(input())) for i in range(n)]
light = 0 # 1番目のボタンが初め光ってる
count = 0
for i in range(n):
light = botan[light] - 1
if light == 1:
break
if i == n - 1:
print((-1))
else:
print((i + 1)) | p03680 |
*a, = list(map(int, open(0).read().split()))
b = a[1]
l = []
for i in range(a[0]):
if b in l:
print((-1))
exit()
elif b == 2:
print((i+1))
exit()
l += [b]
b = a[b] | *a, = list(map(int, open(0).read().split()))
b = a[1]
l = []
for i in range(a[0]):
if b == 2:
print((i+1))
exit()
b = a[b]
print((-1)) | p03680 |
N = int(eval(input()))
a = [int(eval(input())) for i in range(N)]
pushed = [0]
ans = 0
current = 0
while True:
ans += 1
current = a[current] - 1
if current in pushed:
ans = -1
break
if current == 1:
break
pushed.append(current)
print(ans)
| N = int(eval(input()))
a = [int(eval(input())) for i in range(N)]
pushed = [False] * N
ans = 0
current = 0
while True:
ans += 1
current = a[current] - 1
if pushed[current]:
ans = -1
break
if current == 1:
break
pushed[current] = True
print(ans)
| p03680 |
def I(): return int(eval(input()))
def MI(): return list(map(int, input().split()))
def LMI(): return list(map(int, input().split()))
N = I()
A = [I() for _ in range(N)]
seen = {1}
i = 0
light = 1
while light != 2:
light = A[light - 1]
if light in seen:
print((-1))
exit(0)
i... | def I(): return int(eval(input()))
def MI(): return list(map(int, input().split()))
def LMI(): return list(map(int, input().split()))
N = I()
A = [I() for _ in range(N)]
seen = set()
i = 0
light = 1
while light != 2:
seen.add(light)
light = A[light - 1]
if light in seen:
print((-1))
... | p03680 |
# -*- coding:utf-8 -*-
N=int(eval(input()))
button=[]
for i in range(N):
button.append(int(eval(input())))
number=0
count=0
footprint=[0]
while number!=1:
number=button[number]-1
count+=1
if number in footprint:
print((-1))
exit()
footprint.append(number)
print(count) | # -*- coding:utf-8 -*-
import sys
a=[int(i)-1 for i in sys.stdin]
N=a[0]+1
a=a[1:]
done=[False]*N
ans=0
i=0
while True:
if done[i]==False:
done[i]=True
ans+=1
if a[i]==1:
break
i=a[i]
else:
ans=-1
break
print(ans)
| p03680 |
N = int(eval(input()))
button_list =[]
for i in range(1,N+1):
button_list.append([i,int(eval(input()))])
bond_list = [button_list[0][0]]
dest = 0
for i in range(N):
bond_list.append(button_list[button_list[dest][1]-1][0])
bond_list.append(button_list[button_list[dest][1]-1][1])
dest = button_list[butto... | N = int(eval(input()))
button_list =[]
for i in range(1,N+1):
button_list.append(int(eval(input())))
count = 0
dest = 1
for i in range(N):
dest = button_list[dest - 1]
count +=1
if dest == 2:
break;
if count == N:
print((-1))
else:
print(count)
| p03680 |
n = int(eval(input()))
x = [0] + [int(eval(input())) for i in range(n)]
cnt = 1
idx = min(x[1:])
while True:
if x[idx] == 2:
ans = cnt
break
elif x[idx] == x.index(x[idx]):
ans = -1
break
elif x.index(x[idx]) == x.index(min(x[1:])):
ans = -1
break... | def train(n):
x =[0] + [int(eval(input())) for i in range(n)]
idx = 1
for i in range(n+1):
if x[idx] == 2:
return i + 1
idx = x[idx]
return -1
n = int(eval(input()))
print((train(n)))
| p03680 |
N=int(eval(input()))
a=[int(eval(input())) for _ in range(N)]
visited=[1]
old=1
count=0
while 1:
new = a[old-1]
count += 1
if new in visited:
print((-1))
exit()
if new == 2:
print(count)
exit()
old = new
visited.append(new) | N=int(eval(input()))
a=[int(eval(input())) for _ in range(N)]
visited={1,}
old=1
count=0
while 1:
new = a[old-1]
count += 1
if new in visited:
print((-1))
exit()
if new == 2:
print(count)
exit()
old = new
visited.add(new) | p03680 |
N = int(eval(input()))
dic = {}
for i in range(N):
a = int(eval(input()))
dic[i + 1] = a
l = [1]
n = dic[1]
i = 1
flg = False
if n == 2:
print((1))
else:
while n not in l:
l.append(n)
n = dic[n]
i += 1
if n == 2:
flg = True
ans = i
break
if flg:
print... | n = int(eval(input()))
dic = {}
push = [True] * n
for i in range(1, n+1):
a = int(eval(input()))
dic[i] = a
i = 1
cnt = 1
push[0] = False
while True:
if dic[i] == 2:
break
else:
k = dic[i]
if push[k-1]:
i = k
cnt += 1
push[k-1] = False
else:
cnt = -1
... | p03680 |
# https://atcoder.jp/contests/abc065/tasks/abc065_b
def INT(): return int(eval(input()))
def MAP(): return list(map(int, input().split()))
def LIST(): return list(map(int, input().split()))
N = INT()
a = []
for _ in range(N):
a.append(INT() - 1)
light_idx = 0
ans = 0
while True:
light_idx = a... | # https://atcoder.jp/contests/abc065/tasks/abc065_b
def INT(): return int(eval(input()))
def MAP(): return list(map(int, input().split()))
def LIST(): return list(map(int, input().split()))
N = INT()
a = []
for _ in range(N):
a.append(INT() - 1)
light_idx = 0
ans = 0
while True:
light_idx = a... | p03680 |
from functools import reduce
n = int(eval(input()))
a = [int(eval(input())) for _ in range(n)]
rm = {}
for i, x in enumerate(a):
rm.setdefault(x, set()).add(i + 1)
p = set()
for i in range(n):
if 1 in rm.get(2, []):
print((i + 1))
exit(0)
d = rm.get(2, set()) - p
if len(d) == 0: break
... | n = int(eval(input()))
a = [int(eval(input())) for _ in range(n)]
c = 1
for i in range(n):
c = a[c - 1]
if c == 2:
print((i + 1))
exit(0)
print((-1)) | p03680 |
N=int(eval(input()))
a=[int(eval(input())) for i in range(N)]
b=[]
j=1
k=1
if 2 not in a:
print((-1))
else:
while j in range(1,N+1):
if a[k-1] not in b:
b.append(a[k-1])
if a[k-1]==1:
break
elif a[k-1]==2:
break
else:
... | N=int(eval(input()))
a=[int(eval(input())) for i in range(N)]
b=[]
j=1
k=1
c=1
if 2 not in a:
print((-1))
else:
while j in range(1,N+1):
c += 1
if a[k-1]==1:
print((-1))
break
elif a[k-1]==2:
print((c-1))
... | p03680 |
import sys
stdin = sys.stdin
ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
ns = lambda: stdin.readline()
n = ni()
a = [int(ns()) for i in range(n)]
pushed = []
next_b = 1
count = 0
for _ in range(0,n):
if next_b == 2:
break
count += 1
next_b = a[next_b-1... | import sys
stdin = sys.stdin
ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
ns = lambda: stdin.readline()
n = ni()
a = [int(ns()) for i in range(n)]
pushed = {}
next_b = 1
count = 0
for _ in range(0,n):
if next_b == 2:
break
count += 1
next_b = a[next_b-1... | p03680 |
def main():
N = int(eval(input()))
a = [int(eval(input())) for _ in range(N)]
ans = 0
nxt = 1
while True:
if ans > N:
print((-1))
exit()
elif nxt == 2:
break
nxt = a[nxt-1]
ans += 1
print(ans)
if __name__ == ... | def main():
N = int(eval(input()))
a = [int(eval(input())) for _ in range(N)]
tmp = 0
for i in range(N):
if a[tmp] == 2:
print((i+1))
exit()
else:
tmp = a[tmp]-1
print((-1))
if __name__ == "__main__":
main()
| p03680 |
n = int(eval(input()))
a = [0] * n
for i in range(n):
a[i] = int(eval(input()))
ans = 1
num = a[0]
path = []
while num != 2:
if len({num} & set(path)) > 0:
ans = -1
break
path.append(num)
num = a[num-1]
ans += 1
print(ans) | n = int(eval(input()))
a = [0] * (n+1)
for i in range(n):
a[i+1] = int(eval(input()))
ans = 0
idx = 1
for i in range(n-1):
if a[idx] == 2:
print((ans+1))
exit()
else:
ans += 1
idx = a[idx]
print((-1)) | p03680 |
N = int(eval(input()))
a = [list() for i in range(N+1)]
for i in range(N):
b = int(eval(input()))
a[i+1].append(b)
ans = 0
check = []
tmp = 1
check.append(tmp)
flag = False
while(1):
tmp = a[tmp][0]
ans += 1
if tmp==2:
flag = True
break
if tmp in check:
... | N = int(eval(input()))
a = []
for i in range(N):
b = int(eval(input()))
a.append(b)
ans = 0
tmp = 1
flag = False
while(1):
tmp = a[tmp-1]
ans += 1
if tmp==2:
flag = True
break
if ans > N:
break
if flag:
print(ans)
else:
print((-1)) | p03680 |
N = int(eval(input()))
a = []
for i in range(N) :
a.append(int(eval(input())))
index = 1
cnt = 0
while True:
index = a[index - 1]
cnt += 1
if index == 2 :
break
if index == 1 :
cnt = -1
break
print(cnt)
| N = int(eval(input()))
a = []
for i in range(N) :
a.append(int(eval(input())))
index = 1
cnt = 0
for i in range(N):
index = a[index - 1]
cnt += 1
if index == 2 :
break
if index == 1 :
cnt = -1
break
if i == N - 1 :
cnt = -1
print(cnt)
| p03680 |
N = int(eval(input()))
a = [int(eval(input())) for _ in range(N)]
i = 1
c = 0
while True:
i = a[i - 1]
c += 1
if i == 1:
c = -1
break
elif i == 2:
break
print(c)
| N = int(eval(input()))
a = [int(eval(input())) for _ in range(N)]
i = 1
c = 0
ans = -1
for _ in range(N):
i = a[i - 1]
c += 1
if i == 2:
ans = c
break
print(ans)
| p03680 |
n = int(eval(input()))
s = [int(eval(input())) for _ in range(n)]
t = list(range(1,n+1))
i = 1
count = 0
while(i in t):
count += 1
t.remove(i)
i = s[i-1]
if i==2:
print(count)
break
else:
print((-1)) | n = int(eval(input()))
s = [int(eval(input())) for _ in range(n)]
t = set()
i = 1
count = 0
while(i not in t):
count += 1
t.add(i)
i = s[i-1]
if i==2:
print(count)
break
else:
print((-1)) | p03680 |
N = int(eval(input()))
A = [int(eval(input())) for _ in range(N)]
done_list = [1]
ans = 0
tmp = 1
for _ in range(N):
if A[tmp-1] in done_list:
print((-1))
exit(0)
done_list.append(A[tmp-1])
tmp = A[tmp-1]
ans += 1
if tmp == 2:
print(ans)
exit(0) | N = int(eval(input()))
A = [0] + [int(eval(input())) for _ in range(N)]
done = {}
ans = 0
now = A[1]
while True:
ans += 1
if now == 2:
print(ans)
exit(0)
if done.get(now) == None:
done[now] = True
now = A[now]
else:
break
print((-1)) | p03680 |
n = int(eval(input()))
l = []
o = set()
t = 0
c = 0
ans = -1
for i in range(n):
l.append(int(eval(input()))-1)
for i in range(n):
if l[t] == 1:
ans = c+1
break
else:
if t in o:
break
else:
c += 1
o.add(t)
t =... | n = int(eval(input()))
l = []
t = 0
c = 0
ans = -1
for i in range(n):
l.append(int(eval(input()))-1)
for i in range(n):
if l[t]==1:
ans = c+1
break
else:
c +=1
t = l[t]
print(ans) | p03680 |
N = int(eval(input()))
a = [int(eval(input())) for i in range(N)]
button = [0]
on = 0
ans = 0
while True:
now = a[on]-1
ans += 1
if now not in button:
if now == 1:
break
else:
on = now
button.append(now)
else:
ans = -1
... | N = int(eval(input()))
a = [int(eval(input())) for i in range(N)]
on, ans, flg = 0, 0, 0
for i in range(N):
now = a[on]-1
ans += 1
if now == 1:
flg = 1
break
else:
on = now
if flg == 1:
print(ans)
else:
print((-1)) | p03680 |
#ABC065
n = int(eval(input()))
a = [int(eval(input())) for _ in range(n)]
b = []
count = 0
i = 1
for _ in range(n):
if i in b:
count = 0
break
if i == 2:
break
b.append(i)
i = a[i-1]
count += 1
if count != 0:
print(count)
else:... | #ABC065
n = int(eval(input()))
a = [int(eval(input())) for _ in range(n)]
b = []
i = 1
for _ in range(n):
b.append(i)
i = a[i-1]
if 2 in b:
print((b.index(2)))
else:
print((-1)) | p03680 |
n = int(eval(input()))
a = []
for _ in range(n):
a.append(int(eval(input())))
r = []
idx = 0
cnt = 0
for i in range(n):
w = a[idx]
cnt += 1
if w in r:
cnt = -1
break
elif w == 2:
break
elif i == n - 1:
cnt = -1
break
else:
r.... | n = int(eval(input()))
a = [int(eval(input())) for _ in range(n)]
cnt = idx = 0
for i in range(n):
cnt += 1
if a[idx] == 2:
break
if a[a[idx] - 1] == idx + 1:
cnt = -1
break
if i == n - 1:
cnt = -1
break
idx = a[idx] - 1
print(cnt) | p03680 |
N = int(eval(input()))
B = [0] + [int(eval(input())) for _ in range(N)]
x = 1
cnt = 0
while True:
x = B[x]
cnt += 1
if x == 2:
break
if x == 1:
cnt = -1
break
print(cnt)
| N = int(eval(input()))
B = [0] + [int(eval(input())) for _ in range(N)]
x = 1
cnt = 0
dic = {x}
while True:
x = B[x]
cnt += 1
if x == 2:
break
if {x} <= dic:
cnt = -1
break
dic.add(x)
print(cnt)
| p03680 |
N = int(eval(input()))
A = [int(eval(input())) for i in range(N)]
i = 0
cnt = 1
cmpr = [0]
while A[i] != 2:
if A[i] == i + 1:
print((-1))
exit()
i = A[i] - 1
if i in cmpr:
print((-1))
exit()
cmpr.append(i)
cnt += 1
print(cnt) | N = int(eval(input()))
A = [int(eval(input())) for i in range(N)]
i = 0
cnt = 1
cmpr = [0]
while A[i] != 2:
if A[i] == i + 1:
print((-1))
exit()
i = A[i] - 1
cmpr.append(i)
cnt += 1
if cnt > N:
print((-1))
exit()
print(cnt) | p03680 |
n = int(eval(input()))
a_list = [int(eval(input())) for i in range(n)]
count = 1
now_button = 0
for i in range(1, len(a_list)+1):
if a_list[now_button] == 2:
print(count)
exit()
else:
now_button = a_list[now_button]-1
count += 1
print('-1') | n = int(eval(input()))
a_list = [int(eval(input())) for i in range(n)]
count = 1
now_button = 0
for i in range(len(a_list)):
if a_list[now_button] == 2:
print(count)
exit()
else:
now_button = a_list[now_button]-1
count += 1
print('-1') | p03680 |
import sys
input = sys.stdin.readline
n=int(eval(input()))
A = [0]*n
B = [int(eval(input()))-1 for i in range(n)]
C = [0]
def fun(k):
if B[k] in C:
print((-1))
sys.exit()
else:
C.append(B[k])
if B[k] == 1:
return False ... | import sys
input = sys.stdin.readline
n=int(eval(input()))
B = [int(eval(input()))-1 for i in range(n)]
def fun(k):
if B[k] == 1:
return -5
else:
return B[k]
ans = 0
cnt = 0
for i in range(n+1):
cnt = fun(cnt)
ans +=1
... | p03680 |
import sys
input = sys.stdin.readline
n = int(eval(input()))
buttons = [int(eval(input()))-1 for n in range(n)]
light = 0
count = 0
while light != 1:
if buttons[light] == -1:
print((-1))
break
num = light
light = buttons[num]
buttons[num] = -1
count += 1
else:
pr... | import sys
input = sys.stdin.readline
n = int(eval(input()))
buttons = [int(eval(input())) for n in range(n)]
count,light = 1,buttons[0]
while light != 2 and count<n:
count,light = count+1,buttons[light-1]
print((count if count<n else -1)) | p03680 |
import sys
input = sys.stdin.readline
buttons = list(map(int,sys.stdin))
n = buttons[0]
count,light = 1,buttons[1]
while light!=2 and count<n:
count,light = count+1,buttons[light]
print((count if count<n else -1)) | import sys
input = sys.stdin.readline
buttons = list(map(int,sys.stdin))
light = buttons[1]
for i in range(buttons[0]):
if light==2:
print((i+1))
break
light= buttons[light]
else:
print((-1)) | p03680 |
n = int(eval(input()))
nlist = [int(eval(input())) for i in range(n)]
xlist = []
c = 0
x = 1
while x != 2 and x not in xlist and c < n:
xlist.append(x)
x = nlist[x - 1]
c += 1
if x == 2:
print(c)
else:
print((-1))
| n = int(eval(input()))
nlist = [int(eval(input())) for i in range(n)]
c = 0
x = 1
while x != 2 and c < n:
x = nlist[x - 1]
c += 1
if x == 2:
print(c)
else:
print((-1))
| p03680 |
import sys
sys.setrecursionlimit(10 ** 7)
f_inf = float('inf')
mod = 10 ** 9 + 7
def resolve():
n = int(eval(input()))
A = list(int(eval(input())) for _ in range(n))
i = 1
res = 0
for _ in range(n):
i = A[i - 1]
res += 1
if i == 2:
break
... | import sys
sys.setrecursionlimit(10 ** 7)
f_inf = float('inf')
mod = 10 ** 9 + 7
def resolve():
n = int(eval(input()))
A = list(int(eval(input())) for _ in range(n))
j = 1
cnt = 0
for i in range(n):
if j == 2:
break
j = A[j - 1]
cnt += 1
... | p03680 |
N = int(eval(input()))
B = [int(eval(input())) for i in range(N)]
A = [0]
A.extend(B)
past = [1]
next_l = 1
if not 2 in A:
print((-1))
exit(0)
for i in range(N):
next_l = A[next_l]
if next_l in past or next_l > N:
print((-1))
exit(0)
if next_l == 2:
print((len(past)))
exit(0)
... | N = int(eval(input()))
B = [int(eval(input())) for i in range(N)]
A = [0]
A.extend(B)
past = [1]
next_l = 1
#if not 2 in A:
# print(-1)
# exit(0)
for i in range(N):
next_l = A[next_l]
#if next_l in past or next_l > N:
# print(-1)
# exit(0)
if next_l == 2:
print((len(past)))
exit(0)... | p03680 |
# -*- coding: utf-8 -*-
#############
# Libraries #
#############
import sys
input = sys.stdin.readline
import math
#from math import gcd
import bisect
from collections import defaultdict
from collections import deque
from functools import lru_cache
#############
# Constants #
#############
M... | # -*- coding: utf-8 -*-
#############
# Libraries #
#############
import sys
input = sys.stdin.readline
import math
#from math import gcd
import bisect
from collections import defaultdict
from collections import deque
from functools import lru_cache
#############
# Constants #
#############
M... | p03680 |
# ABC 065 B
N = int(eval(input()))
A = [int(eval(input())) for _ in range(N)]
i = 1
q = []
while i != 2:
q.append(i)
i = A[i-1]
if i in q:
print((-1))
break
else:
print((len(q))) | # ABC 065 B
N = int(eval(input()))
A = [int(eval(input())) for _ in range(N)]
i = 1
s = 0
while i != 2:
s += 1
A[i-1], i = 1, A[i-1]
if i == 1:
print((-1))
break
else:
print(s) | p03680 |
N = int(eval(input()))
a = [int(eval(input())) for i in range(N)]
b = a[0]
li = [0]
c = 1
while b != 2:
li += [b-1]
b = a[b-1]
if b-1 in li:
print((-1))
break
else:
c += 1
else:
print(c)
| N = int(eval(input()))
a = [int(eval(input())) for i in range(N)]
b = a[0]
li = [0]
c = 1
while b != 2:
li += [b-1]
b = a[b-1]
c += 1
if c > N:
print((-1))
break
else:
print(c)
| p03680 |
from sys import stdin
if __name__ == "__main__":
_in = [_.rstrip() for _ in stdin.readlines()]
N = int(_in[0]) # type:int
a_arr = [None]
for i in range(N):
_ = int(_in[i+1]) # type:int
a_arr.append(_)
# vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
memo = []
... | from sys import stdin
if __name__ == "__main__":
_in = [_.rstrip() for _ in stdin.readlines()]
N = int(_in[0]) # type:int
a_arr = [None]
for i in range(N):
_ = int(_in[i+1]) # type:int
a_arr.append(_)
# vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
memo = []
... | p03680 |
import sys
input_methods=['clipboard','file','key']
using_method=0
input_method=input_methods[using_method]
IN=lambda : list(map(int, input().split()))
mod=1000000007
#+++++
def main():
a = int(eval(input()))
al=[]
for i in range(a):
b = int(eval(input()))
al.append(b)
opened_list=set()... | import sys
input_methods=['clipboard','file','key']
using_method=0
input_method=input_methods[using_method]
IN=lambda : list(map(int, input().split()))
mod=1000000007
#+++++
def main():
a = int(eval(input()))
al=[]
for i in range(a):
b = int(eval(input()))
al.append(b)
opened_list=set()... | p03680 |
n = int(eval(input()))
butnum = {}
for i in range(1,n+1):
butnum[i] = int(eval(input()))
pushbut = 1
pushedbut =[]
jud = 0
for j in range(1,n+1):
pushedbut.append(pushbut)
pushbut = butnum[pushbut]
if pushbut == 2:
print(j)
jud = 1
break
elif pushbut in pushedbu... | n = int(eval(input()))
butnum = {}
for i in range(1,n+1):
butnum[i] = int(eval(input()))
pushbut = 1
pushedbut =[]
jud = 0
for j in range(1,n+1):
pushbut = butnum[pushbut]
if pushbut == 2:
print(j)
jud = 1
break
if jud == 0:
print((-1)) | p03680 |
N=int(eval(input()))
L=[]
for i in range(N):
L.append(int(eval(input())))
count=0
ans=0
i=0
while(1):
count+=1
if count==N+100:
print((-1))
exit()
i=L[i]-1
ans+=1
if i==1:
print(ans)
exit() | N=int(eval(input()))
L=[]
count=0
t=0
for i in range(N):
L.append(int(eval(input())))
while(1):
count+=1
if count>N+10:
print((-1))
exit()
if L[t]==2:
print(count)
exit()
else:
t=L[t]-1 | p03680 |
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