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.
N = int(input())
A = [int(input()) for i in range(N)]

cnt = 0
pos = 0

while True:
    if pos == 1:
        print(cnt)
    if cnt >= N:
        print(-1)

    pos = A[pos] - 1
    cnt += 1
N = int(input())
A = [int(input()) for i in range(N)]

cnt = 0
pos = 0

while True:
    if pos == 1:
        print(cnt)
        break
    if cnt >= N:
        print(-1)
        break

    pos = A[pos] - 1
    cnt += 1