using System;

public class Program

{

    public static void Main()

    {

        long ret = SumSquareDiff(100);

        Console.WriteLine(ret);

    }

    public static long SumSquareDiff(long x)

    {

        long sumSquare = 0;

        long squareSum = 0;

        for (long i = 1; i <=x; i++)

        {

                sumSquare+=i*i;

                squareSum+=i;

        }

        squareSum = squareSum*squareSum;

        return squareSum-sumSquare;

    }

}