using System;

public class Program

{

    public static void Main()

    {

        string nome = "Rafael";

        nome.ChangeName();

        Console.WriteLine(nome.GetHashCode());

        Console.WriteLine(nome);

    }

}

​

public static class Abc

{

    public static string ChangeName(this string name)

    {       

        name = "Maria";

        Console.WriteLine(name.GetHashCode());

        return name;

    }   

}