#include <iostream>
#include <fstream>
#include <iomanip>
using namespace std;

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

long long v[5000003], r;

int main()
{
int d, i, k, q, p=1, j, nr=0;
f>>r>>d;
for (i=1;i<=r/2;i++)    {
if ((r-i+1)%d==0)
    k=d;
else
    k=(r-i+1)%d;
if (i%d==0)
    q=d;
else
    q=i%d;
p= (p * k/q) % d;
if (p==0)   {
    nr++;//Rezultatul (cati divizibili)
    p=d;
}
}
nr = nr *2;
if (r%2==0) {
    i=r/2 + 1;
    if ((r-i+1)%d==0)
    k=d;
else
    k=(r-i+1)%d;
if (i%d==0)
    q=d;
else
    q=i%d;
p= (p * k/q) % d;
if (p==0)   {
    nr++;//Rezultatul (cati divizibili)
    p=d;
}
}
g<<nr;
    return 0;
}