triagls

#include <iostream>
using namespace std;

int main() {
    long long n;
    cin >> n;
    long long u = 0, k = n, a = n;

    for (int i = 0; i < a; i++){
        for (int j = 1; j <= n; j++){
            u += j;
        }
        n -= 1;
    }
    for (int i = k - 1; i > 0; i -= 2){
        for (int j = 1; j <= i; j++){
            u += j;
        }
    }
    cout << u;
}