#include <fstream>

using namespace std;

int main()
{
    ifstream in("fractii.in");
    ofstream out("fractii.out");

    int n, i, j, nf;

    in >> n;

    nf = n;
    for (i = 2; i <= n; i++) {
        nf++;
        for (j = 2; j < i; j++)
            if (i % j != 0)
                nf++;
        for (j = i + 1; j <= n; j++)
            if (j % i != 0)
                nf++;
    }

    out << nf;

    in.close();
    out.close();

    return 0;
}