#include <fstream>

int Lcd(int a, int b) {
    while (b) {
        int r = a % b;
        a = b;
        b = r;
    }
    return a;
}

int main() {
    std::ifstream fin("fractii.in");
    std::ofstream fout("fractii.out");

    int n, result = 0;

    fin >> n;

    for (int i = 2; i < n; i++) {
        for (int j = i + 1; j <= n; j++) {
            if (Lcd(i, j) == 1) {
                result += 2;
            }
        }
    }
    result += 2 * n - 1;

    fout << result;

    return 0;
}