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())
button=[int(input()) for i in range(n)]
check=[]
temp=1
ans=0
while button[temp-1] not in check:
  button.append(temp)
  temp=button[temp-1]
  ans+=1
  if button[temp-1]==2:
    print(ans)
    break
  elif button[temp-1] in check:
    print(-1)
    break
n=int(input())
button=[int(input()) for i in range(n)]
temp=1
ans=0
while True:
  temp=button[temp-1]
  ans+=1
  if temp==2:
    print(ans)
    break
  elif ans>=n:
    print(-1)
    break
