#include <fstream>

using namespace std;

long long S, P, N;
long long R;
int u;

ifstream cin ( "suma.in" ) ;
ofstream cout ( "suma.out") ;


int main()
{

    cin >> N, cin >> P ;

    if( N % 2 == 0 )
       {

        S = N * (N + 1) * (N - 1) / 3 ;
        cout << S;
       }
    else S = N * (N - 1 ) *  (N - 2 ) / 3 + N * ( N -1 ) ;
    cout << S;
//R = long (S % P) ;
    //cout << ' ' << R;



    cin.close();
    cout.close();
    return 0;
}