// Numarul fractiilor ireductibile care se pot forma
// cu toate numerele naturale de la 1 la n

#include <iostream>
#include  <fstream>

using namespace std;

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

int main()
{
    int n, sol, red = 0;
    int i, j;
    f>>n;

    sol = n*n;

    //bool div[n][n] = {0};
    for(i = 2; i<n; i++) {
        //red += (d/i - 1)*(d/i)/2;
        //red += (d/i - 1)*(d/i)/2;
        int ci = i, d=2;
        while(ci>1) {
            if(ci%d == 0) {
                while(ci%d == 0) ci /= d;
                red += (n-i)/d;
            }
            d++;
        }
    }

    red = red*2;
    red += n-1;
    sol -= red;
    g << sol;

    return 0;
}