#include <bits/stdc++.h>
#define herta return 0;
using namespace std;
int N;
int ans;
bool v[10000005];
void primes(int n) {
	for (int i = 2; i <= n; ++i) v[i] = 1;
	for (int i = 2; i <= n; ++i) {
		if (!v[i]) continue;
		for (int j = i; j <= n / i; ++j)
			v[i * j] = 0;
	}
}
int main() {
	freopen("gcd_prime.in", "r", stdin);
	freopen("gcd_prime.out", "w", stdout);
	primes(10000000);
	cin >> N;
	for (int x = 1; x <= N; x++) {
		for (int y = x; y <= N; y++) {
			if (v[__gcd(x,y)]) ans++;
			if (x != y && v[__gcd(x,y)]) ans++;
			}
	}
	cout << ans << endl;
	herta
}