using System;

​

public class Program

{

    public static void Main()

    {

        double squaredSum = 0;

        for (int b = 1; b <= 100; b++)

            squaredSum += Math.Pow(b, 2);

        double sumSquared = 0;

        for (int a = 1; a <= 100; a++)

            sumSquared += a;

        sumSquared = Math.Pow(sumSquared, 2);

        Console.WriteLine(Math.Abs(squaredSum - sumSquared));

    }

}