#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using ld = long double;
using mint = modint998244353;

int main() {
  int N; cin >> N;
  ll ans = 0;
  for (ll i = 1; i <= N; i++) {
    if (i % 3 == 1) ans += i;
    if (i % 3 == 2) ans += i * i;
    if (i % 3 == 0) ans += i * i * i;
  }
  cout << ans << endl;
}