a,b=map(int,input().split())
n=0
sum=0
if b==0:
        print('1')
        exit()
elif a*b==-b:
        print('2')
        exit()
for i in range(3,(max(a,b))):
        sum+=a**i
        if sum==-1:
                print(i)
                exit()
print('-1')