import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    static long sumOfGroup(int k) {
        long left = (k + 1) * ( k + 1);
        long right = (k - 1) * (k - 1);
        long inside = left - right;
        inside = inside / 4;
        inside = inside * k * k;
        return inside;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int k = in.nextInt();
        long answer = sumOfGroup(k);
        System.out.println(answer);
        in.close();
    }
}