INF = 10 ** 10
import sys
sys.setrecursionlimit(100000000)
dy = (-1,0,1,0)
dx = (0,1,0,-1)
from  collections import deque

def main():
    n, P = map(int,input().split())
    G = [[] for _ in range(n + 1)]
    primes = [1] * (n + 1)
    for p in range(2,n + 1):
        if primes[p]:
            for i in range(2 * p,n + 1,p):
                primes[i] = 0
                G[i].append(p)
                G[p].append(i)
    
    stack = []
    stack.append(P)
    visited = [0] * (n + 1)
    visited[P] = 1
    while stack:
        p = stack.pop()
        for v in G[p]:
            if visited[v]:
                continue
            else:
                visited[v] = 1
                stack.append(v)
    
    print(sum(visited))

if __name__ == '__main__':
    main()