n, k = list(map(int, input().split()))
maxA = n-k

primeSet = set()
primeList = [True] * int(3 + maxA ** 0.5)

primeList[1] = False
primeList[2] = True
primeSet.add(2)
for i in range(4, len(primeList), 2):
    primeList[i] = False

for i in range(3, len(primeList)):
    if primeList[i] == True:
        for j in range(i*2, len(primeList), i):
            primeList[i] = False
        primeSet.add(i)

ans = 1
if k == 0:
    ans += 1
pFactor = []
while maxA > 1:
    for p in primeSet:
        if maxA % p == 0:
            pFactor.append(p)
            maxA //= p
            continue
    break
ans += len(pFactor)
print(ans)