#include <bits/stdc++.h>
using namespace std;
ifstream in("pascal.in");
ofstream out("pascal.out");
int n,k,nr,i,p=1;
int cmmdc(int a, int b)
{
    int r;
    while(b)
    {
        r=a%b;
        a=b;
        b=r;
    }
    return a;
}
int main()
{
    in>>n>>k;
    if(k==1)
    {
        out<<n+1;
        return 0;
    }
    for(i=1; i<=n/2; i++)
    {
        nr=(n-i+1)/i;
        p*=cmmdc(nr,k);
        if(p%k==0)
            break;
    }
    if(p%k==0)
        out<<n+1-2*i;
    else out<<0;

}