Takahashi wants to gain muscle, and decides to work out at AtCoder Gym.  The exercise machine at the gym has N buttons, and exactly one of the buttons is lighten up. These buttons are numbered 1 through N. When Button i is lighten up and you press it, the light is turned off, and then Button a_i will be lighten up. It is possible that i=a_i. When Button i is not lighten up, nothing will happen by pressing it.  Initially, Button 1 is lighten up. Takahashi wants to quit pressing buttons when Button 2 is lighten up.  Determine whether this is possible. If the answer is positive, find the minimum number of times he needs to press buttons.
# ABC065 B - Trained?
N = int(input())

A = [[int(input()),False] for i in range(N)]
print(A)
idx = 0
A[0][1] == True
cnt = 1

while cnt != N:
    if A[idx][1]:
        print(-1)
        exit()
    if A[idx][0] == 2:
        print(cnt)
        exit()
    A[idx][1] = True
    idx = A[idx][0]-1
    cnt += 1
n=int(input())
a=[int(input()) for i in range(n)]
btn=[0]*n
ans=1
i=0
while True:
  if btn[i]==1:
    print(-1)
    exit()
  if a[i]==2:
    print(ans)
    exit()
  btn[i]=1
  i=a[i]-1
  ans+=1
