import math
N,P=map(int,input().split())

def searchPrimeNum(N):
  max = int(math.sqrt(N))
  searchList = [i for i in range(2,N+1)]
  primeNum = []
  while searchList[0] <= max:
    primeNum.append(searchList[0])
    tmp = searchList[0]
    searchList = [i for i in searchList if i % tmp != 0]
  primeNum.extend(searchList)
  return primeNum

class UnionFind:
    def __init__(self, n):
        self.n = n
        self.p = [e for e in range(n)]
        self.rank = [0] * n
        self.size = [1] * n

    def same(self, u, v):
        return self.find_set(u) == self.find_set(v)

    def unite(self, u, v):
        u = self.find_set(u)
        v = self.find_set(v)

        if u == v:
            return

        if self.rank[u] > self.rank[v]:
            self.p[v] = u
            self.size[u] += self.size[v]
        else:
            self.p[u] = v
            self.size[v] += self.size[u]
            if self.rank[u] == self.rank[v]:
                self.rank[v] += 1

    def find_set(self, u):
        if u != self.p[u]:
            self.p[u] = self.find_set(self.p[u])

        return self.p[u]

    def update_p(self):
        for u in range(self.n):
            self.find_set(u)

    def get_size(self, u):
        return self.size[self.find_set(u)]

if P==1:
  print(1)
else:
  uf=UnionFind(N)
  table=searchPrimeNum(N)
  for v in table:
    i=2
    while v*i<=N:
      uf.unite(v-1,v*i-1)
      i+=1
  print(uf.get_size(P-1))