#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

long sumOfGroup(int k) {
    ll n = (k * (ll)(k-1));
    n *= k;
    n += k * (ll)k;
    return n;
}

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