#include <fstream>

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

int main() {
    std::ifstream f("fractii.in");
    std::ofstream g("fractii.out");
    int n;
    f >> n;
    int nr = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = i; j <= n; j++) {
            if (cmmdc(i, j) == 1) {
                nr += 2;
            }
        }
    }
    g << nr - 1;
}