using System;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("***** Welcome *****");

        do

        {

            Console.WriteLine("***** Enter any real number *****");

            string strNumber = Console.ReadLine();

            int number = int.Parse(strNumber);

            string resultString;

            switch (number)

            {

                case 4:

                    resultString = "exactly 4";

                    break;

                case 5:

                case 6:

                    resultString = "5 or 6";

                    break;

                default: //optional

                    resultString = "not 4, 5 or 6";

                    break;

            }

​

            Console.WriteLine("Your number is " + resultString);

        }

        while (true);

    }

}