#pragma comment (linker, "/STACK:64000000")
#include <iostream>
#include <string>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <map>
#include <stack>
#include <climits>
#include <cmath>
#include <vector>
#include <queue>
#include <iomanip>
#include <unordered_map>
#include <set>
#include <stdio.h>
#include <string.h>
 
using namespace std;
 
const int N6 = 1e6 + 6;
const int N9 = 1e9 + 7;
 
 
typedef unsigned long long ull;
typedef long long ll;
typedef double ld;
typedef pair <int, int> PII;
typedef pair <int, ll> PIl;
typedef pair <ll, int> PlI;
typedef pair <ll, ll> Pll;
 
#define y1 UKG_KTL
#define F first
#define S second
#define pb push_back
#define mp make_pair
#define itn int
#define forn(x, a, b) for (int x = a; x <= b; ++x)
#define for1(x, a, b) for (int x = b; x >= a; --x)
#define sz() size()
#define skip continue
#define gg exit(0)
#define boost ios_base::sync_with_stdio(0),cin.tie(NULL)
#define N 50
 
// const unsigned long long N = 2 * 1e5;
const ll INFLL = (ll)1e18 + 100;
const int INF = 1e9 + 100;
const ll mod = 1e9 + 9;
const ll P = 31;

ll n;

void solve(){

  cin >> n;

  ll kep = n * (n + 1) / 2;
  --n;
  ll kepp = n * (n + 1) / 2;
  cout << kep*kep - kepp*kepp;


}
 
int main(){
  #define task "C"




  #ifdef UKG_KTL
  
   freopen(task".in", "r", stdin);
   freopen(task".out", "w", stdout);
 
  #endif
 
  int tt = 1;
  // boost;
  // srand(time(NULL));
  // scanf ("%d", &tt);
  while (tt--) {
    // cout<<fixed;cout.precision(5);
    solve();
  }
 
  return 0;
}