#include <bits/stdc++.h>
using namespace std;

long sumOfGroup(int ki) {
    long k = (long)ki;
    k--;
    long nk = (k+1) * k / 2;
    long nkn = (k+2) * (k+1) / 2;
    
    long a1 = nk * 2 + 1;
    long a2 = nkn * 2 - 1;
    
    return (a2+a1) * (nkn - nk) / 2;
}

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