using System;

public class Program

{

    public static void Main()

    {

        // The sum of the squares of the first ten natural numbers is,

            // 12 + 22 + ... +102 = 385

            // 

            // The square of the sum of the first ten natural numbers is,

            // (1 + 2 + ... + 10)2 = 552 = 3025.

            // Hence the difference between the sum of the squares of the 

            // first ten natural numbers and the square of the sum is 3025 − 385 = 2640.

            //

            // Find the difference between the sum of the squares of the first  

            // one hundred natural numbers and the square of the sum.

​

            int a = 1;

            int b = 100;

            int Result = SquareOfSum(a, b) - SumOfSquares(a, b);

            int x = SquareOfSum(a, b);

            int y = SumOfSquares(a, b);

​

            Console.WriteLine("The Square of the Sum is: {0:n0}", x);

            Console.WriteLine("The Sum of the Squares is: {0:n0}", y);

            Console.WriteLine("The difference between the sum of the squares of the " +

                "first one hundred natural numbers and the square of the sum is: {0:n0}", Result);

    }

    static int SumOfSquares(int from, int to)

        {

            int SumSquares = 0;

            for (int i = from; i <= to; i++)

            {

                int product = i * i;

                SumSquares += product;

            }

            return SumSquares;

        }

​

        static int SquareOfSum(int from, int to)

        {

            int SquareSum = 0;

            int sum = 0;

            for (int i = from; i <= to; i++)

            {

                sum += i;

            }

            SquareSum = sum * sum;

            return SquareSum;

        }

}