#include <fstream>

using namespace std;

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

int cmmdc(int a, int b)
{
    return b != 0 ? cmmdc(b, a % b) : a;
}

int main()
{
    int n, s = 0;
    f >> n;
    for (int i = 2; i <= n; i++)
        for (int j = 1; j <= i; j++)
            s += cmmdc(i, j) == 1 ? 2 : 0;
    g << 1 + s;
    return 0;
}