#include <iostream>
#include <fstream>
using namespace std;
int n,nr,i,x=2;
int main()
{
    ifstream fin("fractii.in");
    ofstream fout("fractii.out");
    fin>>n;
    nr=n+n-1;
    while(x<=n)
    {
        i=2;
        while(i<=n)
        {
            if(x%i==0 || i%x==0) i++;
            else
             {
                 nr++; i++;
             }
        }
        x++;
    }

    fout<<nr;
    fin.close();
    fout.close();
    return 0;
}