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())
List = [int(input()) for _ in range(n)]
s = List[0]
count = 1
while s!=2 and count<n:
    count+=1
    s = List[s-1]
print(count if count>=n else -1)
n = int(input())
List = [int(input()) for _ in range(n)]
c, s = 1, List[0]
while s!=2 and c<n:
    c+=1
    s = List[s-1]
print(-1 if c>=n else c)