#include <iostream>
#include <fstream>
#define NMAX 5000000

using namespace std;

ifstream f("pascal.in");
ofstream g("pascal.out");

int n, p, ans, nr[NMAX+10];

void precalc()
{   for(int d=p; d<=n; d*=p)
        for(int i=d; i<=n; i+=d) nr[i]++;
}

int main()
{
    f >> n >> p;
    precalc();
    int val = 0, st = 1, dr = n;
    for(int i=1; i<=n; i++)
        {   val = val + nr[dr] - nr[st];
            st++;
            dr--;
            if(val) ans++;
        }
    g << ans << '\n';
    return 0;
}