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)]
B = 1
for j in(A):
  if j == 2:
    print(B)
    break
  else:
    B += 1
   
   
N = int(input())
A = [int(input()) for i in range(N)]
B = 0
C = 1
for j in range(N):
  if A[B] == 2:
    print(C)
    break
  elif j == N-1:
    print('-1')
  else:
    B = A[B]-1
    C += 1