using System;

public static class Program

{

    public static T Then<T>(this T val, Func<T,T> fn )

    {

        return fn(val);

    }

    public static void Main()

    {

        string cadena = "Hello";

        var superresult = cadena

            .Then(ReturnWorld)

            .Then(AddWelcome);

        Console.WriteLine(superresult);

    }

    public static string ReturnWorld(string param){

        return param + " World" ;

    }

    public static string AddWelcome(string param){

        return param + " And Welcome";

    }

}