A, B = map(int, input().split())
N = B
L = [B]
K = 0

if A > 0 and B > 0:
    K = -1
elif B == 0:
    K = 1
else:
    while N != 0:
        N = A * N + B
        if N == 0:
            K = len(L) + 1
            break
        else:
            if N in L:
                K = -1
                break
            else:
                L.append(N)
            
print(K)