// you can also use imports, for example:
// import java.util.*;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(int[] A) {
        // write your code in Java SE 8
    }
}

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    pass

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1

    for i in A:
        

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1

    for i in A:
        if A[i] == -1:
            

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1

    
        if A[i] == -1:

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1

    while True:
        if A[i] == -1:

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1
    
    while True:
        if A[i] == -1:

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1
    i=0
    while True:
        if A[i] == -1:

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1
    i=0
    while True:
        if A[i] == -1:
            brea;
        elif

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1
    i=0
    while True:
        if A[i] == -1:
            break;
        elif:
            answer+=1
    return answer

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1
    i=0
    while True:
        if A[i] == -1:
            break;
        else:
            answer+=1
    return answer

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1
    i=0
    while True:
        if A[i] == -1:
            break;
        else:
            i = A[i]
            answer+=1
    return answer

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1
    i=0
    while True:
        if A[i] == -1:
            break;
        else:
            i = A[i]
            answer+=1
    return answer

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1
    i=0
    while True:
        if A[i] == -1:
            break;
        else:
            i = A[i]
            answer+=1
    return answer

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1
    i=0
    while True:
        if A[i] == -1:
            break;
        else:
            i = A[i]
            answer+=1
    return answer

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1
    i=0
    while True:
        if A[i] == -1:
            break;
        else:
            i = A[i]
            answer+=1
    return answer

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1
    i=0
    while True:
        if A[i] == -1:
            break;
        else:
            i = A[i]
            answer+=1
    return answer

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1
    i=0
    while True:
        if A[i] == -1:
            break;
        else:
            i = A[i]
            answer+=1
    return answer

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1
    i=0
    while True:
        if A[i] == -1:
            break;
        else:
            i = A[i]
            answer+=1
    return answer

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1
    i=0
    while True:
        if A[i] == -1:
            break;
        else:
            i = A[i]
            answer+=1
    return answer

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    answer=1
    i=0
    while True:
        if A[i] == -1:
            break;
        else:
            i = A[i]
            answer+=1
    return answer