#include <iostream>
#include <fstream>

unsigned long long gcd(unsigned long long a, unsigned long long b) {
    unsigned long long temp;
    while (b != 0) {
        temp = b;
        b = a % b;
        a = temp;
    }
    return a;
}

unsigned long long count_fractions_slow(unsigned long long n) {
    unsigned long long count = 1;
    for (unsigned long long i = 1; i <= n; ++i) {
        for (unsigned long long j = i + 1; j <= n; ++j) {
            if (gcd(i, j) == 1) {
                count += 2;
            }
        }
    }
    return count;
}

int main(int argc, char* argv[]) {

    std::ifstream in("fractii.in");
    unsigned long long n;
    in >> n;
    in.close();

    unsigned long long fraction_count = count_fractions_slow(n);
    std::ofstream out("fractii.out");
    out << fraction_count << '\n';
    out.close();

    return 0;
}