import sys

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

A,B = map(int, read().split())

def solve(A,B):
    N = 0
    for k in range(100):
        N = A * N + B
        if N == 0:
            return k+1
    return -1

print(solve(A,B))