a,b = map(int,input().split())
if b == 0:
    print(1)
    exit()
if a >= 0:
    print(-1)
    exit()

for i in range(2,20):
    count = 0
    for j in range(i):
        count += a**j
    if count == 0:
        print(i)
        exit()
print(-1)