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 _ in range(n)]
s,c = a[0],1
while s != 2 and c < n:
    s = a[s-1]
    c += 1
    print(s)
print(c if c < n else -1)

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