from collections import defaultdict

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[j] = False
        primeSet.add(i)
# print(sorted(primeSet))
ans = 0
pFactor = defaultdict(lambda: 0)
cnt = 0
while maxA > 1:
    flag = False
    # print(pFactor)
    for p in primeSet:
        if maxA % p == 0:
            pFactor[p] += 1
            maxA //= p
            cnt += 1
            flag = True
            continue
    if cnt == 0:
        pFactor[maxA] += 1
    if not flag:
        break

facSet = set()

pKey = sorted(pFactor.keys())
# print(pKey)
def recurPrime(pIndex, n):
    if pIndex == len(pKey):
        facSet.add(n)
    else:
        for i2 in range(pFactor[pKey[pIndex]]+1):
            recurPrime(pIndex+1, n*(int(pKey[pIndex])**i2))

for i in range(pFactor[pKey[0]]+1):
    recurPrime(1, pKey[0]**i)

facRemove = set()
for f in facSet:
    if f <= k:
        facRemove.add(f)
facSet = facSet - facRemove

# print(facSet)
ans += len(facSet)
print(ans)