import sys

sys.setrecursionlimit(10 ** 6)
stdin = sys.stdin

ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
ns = lambda: stdin.readline().strip()
ntp = lambda: tuple(map(int, stdin.readline().split()))
mod = 10 * 9 + 7
inf = 2 << 60

a, b = na()
n = b
cnt = 1
while n:
    cnt += 1
    n2 = a * n + b

    if abs(n2) >= abs(n):
        cnt = -1
        break

    n = n2

print(cnt)