using System;

public class Test
{
	public static void Main()
	{
		IComputer computer = new KeyBoard(new Monitor(new Disk(new Computer())));

		Console.WriteLine(" You are getting a " + computer.getComputer());
	}
}

public interface IComputer
{
	string getComputer();
}

public sealed class Computer : IComputer
{
	public string getComputer()
	{
		return "computer";
	}
}

public class Disk : IComputer
{
	IComputer computer;
	public Disk(IComputer c)
	{
		computer = c;
	}

	public String getComputer()
	{
		return computer.getComputer() + " and a disk";
	}
}

public class Monitor : IComputer
{
	IComputer computer;
	public Monitor(IComputer c)
	{
		computer = c;
	}
	
	public String getComputer()
	{
		return computer.getComputer() + " and a Monitor";
	}
}

public class KeyBoard : IComputer
{
	IComputer computer;
	public KeyBoard(IComputer c)
	{
		computer = c;
	}

	public  String getComputer()
	{
		return computer.getComputer() + " and a KeyBoard";
	}
}