#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

long sumOfGroup(int k) {
    // Return the sum of the elements of the k'th group.
    ll nu = ll(k)*ll(k-1)/2LL;
    ll snu = nu * nu;
    ll nu2 = ll(k)*ll(k+1)/2LL;
    ll snu2 = nu2 * nu2;
    return (snu2-snu);
}

int main() {
    int k;
    cin >> k;
    long answer = sumOfGroup(k);
    cout << answer << endl;
    return 0;
}