n,k = map(int, input().split())
ans = 0
def divisors(num):
    divisors = [1]
    if  num == 1:
        return divisors
    for i in range(2, num//2+1):
        if num % i == 0:
            divisors.append(i)
    divisors.append(num)
    return divisors
ans = divisors(n-k)
pos = 0
for i in range(len(ans)):
    if ans[i] >= k:
        pos = i
        break
print(len(ans)-pos)