/* -*- coding: utf-8 -*-
 *
 * 2174.cc:  No.2174 3 O'clock Easy - yukicoder
 */

#include<cstdio>
#include<algorithm>
 
using namespace std;

/* constant */

/* typedef */

typedef long long ll;

/* global variables */

/* subroutines */

/* main */

int main() {
  int n;
  scanf("%d", &n);

  ll sum = 0;
  for (int i = 1; i <= n; i++)
    switch (i % 3) {
    case 1: sum += i; break;
    case 2: sum += i * i; break;
    case 0: sum += (ll)i * i * i; break;
    }

  printf("%lld\n", sum);

  return 0;
}