using System;

public class program

{

    public static void Main()

    {

        string menu;

        while(true)

        {

            Console.WriteLine("Menu");

            Console.WriteLine("Press 1 Input data[5]");

            Console.WriteLine("Press 2 Display sum");

            Console.WriteLine("Press 3 Display average");

            Console.WriteLine("Press 4 Exit");

            Console.Write("Please enter menu : ");

            menu = Console.ReadLine();

            if(menu=="1")

            {

                Console.WriteLine("Your choose 1st menu");

            }

            else if(menu=="2")

            {

                Console.WriteLine("Your choose 2nd menu");

            }

            else if(menu=="3")

            {

                Console.WriteLine("Your choose 3rd menu");

            }

            else if(menu=="4")

            {

                Console.WriteLine("Your choose 4th menu");

            }

            else 

            {

                Console.WriteLine("Please choose 1-4th menu only");

            }

        }

    }

}