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

idx = 1
flag = False
for i in range(1, N+1):
  idx = A[idx - 1]
  if idx == 2:
    flag = True
    break

if flag:
  print(i + 1)
else:
  print(-1)
N = int(input())
A = []
for i in range(N):
  A.append(int(input()))

idx = 1
flag = False
for i in range(1, N+1):
  idx = A[idx - 1]
  if idx == 2:
    flag = True
    break

if flag:
  print(i)
else:
  print(-1)