#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

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