#include <bits/stdc++.h>

using namespace std;

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

int cmmdc(int a, int b) {
    if (b == 0) {
        return a;
    }
    return cmmdc(b, a % b);
}

int main() {
    int n;
    in >> n;

    int sol = 1;
    for (int i = 1; i <= n; i++) {
        for (int j = i + 1; j <= n; j++) {
            if (cmmdc(i, j) == 1) sol += 2;
        }
    }

    out << sol;

    return 0;
}