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";
	}
}
 

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