using System;

public class Program

{

    public static void Main()

    {

        char option;

        do

        {

            Console.WriteLine("Select");

            option = char.Parse(Console.ReadLine());

​

            switch (option)

            {

                case '1':

                    Console.WriteLine("Result:");

                    Console.WriteLine("1");

                    break;

                case '2':

                    Console.WriteLine("Result:");

                    Console.WriteLine("2");

                    break;

                case '3':

                    Console.WriteLine("Result:");

                    Console.WriteLine("3");

                    break;

            }       

        }

        while(option != '1' && option != '2');  

        Console.WriteLine("The end");

    }

}