using System;

public class Program

{

    public static void Main()

    {

        // first example:

        int sum=0;

        int number = 1;                                           

        do 

        {                                                                 

            //Console.WriteLine(number);

            sum = sum+number;

            number++;                                               

        } while (number < 101);

        Console.WriteLine("the sum of the first 100 numbers is: " + sum);

    }

}