using System;

public class Program

{

    public static void Main()

    {

        Person p = new Person();

        Messager mes = new Messager();

        p.SetName();

        mes.SayHello(p.Name);

    }

}

public class Person

{

    public string Name { get; private set; }

    public void SetName()

    {

        Console.WriteLine("What's your name?");

        Name = Console.ReadLine();

    }

}

​

public class Messager

{

    public void SayHello(string name)

    {

        Console.WriteLine(String.Format("Hello, {0}!", name));

    }

}