#include <iostream>
using namespace std;
int main (){
    int n;
    cin >> n;
    int a = 0;
    for (int i = 0; i < n+1; ++i){
        for (int j = 0; j < i+1; ++j){
            a = a + j + i;
        }
    }
    cout << a;
    return 0;
}