#include <bits/stdc++.h>
using namespace std;

using ll = long long;
#define rep(i, n) for(ll i = 0; i < n; i++)

int main() {
	int N;
	cin >> N;
	ll ans = 0;
	for(int i = 1; i <= N; i++) {
		ll k = i / 3, m = i % 3;
		if(m) {
			m = 3 - m;
			k++;
			if(m == 1) ans += 3 * k - 2;
			else {
				ll a = 3 * k - 1;
				ans += a * a;
			}
		}
		else {
			ll a = 3 * k;
			ans += a * a * a;
		}
	}
	cout << ans << endl;
}