using System;

public class Program

{

    public static void Main()

    {

        int num, x, i;

            x = 0;

            i = 0;

​

            Console.Write("Enter the Number: ");

            num = Convert.ToInt32(Console.ReadLine());

​

            do

            {

​

                x = x + i;

                i++;

​

            } while (i <= num);

​

            Console.WriteLine("\nSum of numbers 1 to 5 is:  " +x);

            Console.ReadLine();

​

    }

}