#include <bits/stdc++.h>
using namespace std;
int n, ans;
bool o[10000005];
int main () {
    freopen ("gcd_prime.in", "r", stdin);
    freopen ("gcd_prime.out", "w", stdout);
    cin >> n;
    o[1] = true;
    for (int i = 2; i <= n; i++) {
        if (o[i] == true) continue;
        for (int j = i * 2; j <= n; j += i) {
            o[j] = true;
        }
    }
    for (int i = 2; i <= n; i++) {
        for (int j = 2; j <= n; j++) {
            if (o[__gcd(i, j)] == false) ans++;
        }
    }
    cout << ans;
    return 0;
}