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

int main() {
    int n, i, d, ci, p;
    long long rez = 0, aux;
    ifstream f("fractii.in");
    f >> n;
    f.close();
    rez += n;
    for (i = 2; i <= n; i++) {
        aux = 0;
        d = 2, ci = i;
        while (ci != 1) {
            p = 0;
            while (ci % d == 0) {
                p++;
                ci /= d;
            }
            if (p)
                aux += ((n / d) - 1);
            d++;
            if (d * d > ci)
                d = ci;
        }
        aux++;
        rez += (n - aux);
    }
    ofstream g("fractii.out");
    g << rez;
    g.close();
    return 0;
}