#pragma GCC optimize ( "O3" )
#pragma GCC target ( "avx" )
#include <bits/stdc++.h>
using namespace std;

using ll = long long;

#define TYPE_OF( VAR ) remove_const<remove_reference<decltype( VAR )>::type >::type
#define UNTIE ios_base::sync_with_stdio( false ); cin.tie( nullptr ) 
#define CEXPR( LL , BOUND , VALUE ) constexpr const LL BOUND = VALUE 
#define CIN( LL , A ) LL A; cin >> A 
#define ASSERT( A , MIN , MAX ) assert( MIN <= A && A <= MAX ) 
#define CIN_ASSERT( A , MIN , MAX ) CIN( TYPE_OF( MAX ) , A ); ASSERT( A , MIN , MAX ) 
#define QUIT return 0 
#define COUT( ANSWER ) cout << ( ANSWER ) << "\n"; 
#define RETURN( ANSWER ) COUT( ANSWER ); QUIT 

int main()
{
  UNTIE;
  CEXPR( ll , bound_N , 10000 );
  CIN_ASSERT( N , 1 , bound_N );
  ll Nq = N / 3;
  ll Nq2 = ( Nq * ( Nq + 1 ) ) / 2;
  ll Nr = N % 3;
  RETURN( 27 * Nq2 * Nq2 + ( 6 * Nq2 - 1 ) * Nq + ( Nr == 0 ? 0 : Nr == 1 ? N : ( N * ( N + 1 ) - 1 ) ) );
}