#include "bits/stdc++.h"

using namespace std;

void solve(void)
{
	long n;
	cin >> n;
	cout << (n-1)*n*(n+1)*(3*n+2)/24 << endl;
}

int main()
{
	solve();
	//cout << "yui(*-v・)yui" << endl;
	return 0;
}