#include <fstream>

using namespace std;

ifstream in("fractii.in");
ofstream out("fractii.out");

int k;

int main()
{
    int n,i,j,k2;
    in>>n;


    i=2;
    while(i<=n)
    {

        j=2;
        while(j<=n)
        {
            if(i%j!=0 || j%i!=0) k++;
            j++;
        }
        i++;
    }

    k2=k+1;

    out<<k2;



    return 0;
}