using System;
using System.Collections.Generic;
public interface ValueGetter { List<int> Get(List<int> values); }
public class PlainGetter : ValueGetter {
	public List<int> Get(List<int> values) { return values; }
}
public abstract class Decoratable {
	protected ValueGetter getter;
	public Decoratable(ValueGetter getter) { this.getter = getter; }
}
public class EvenGetter : Decoratable, ValueGetter { 
	public EvenGetter(ValueGetter getter) : base(getter) {}
	public List<int> Get(List<int> values) { return getter.Get(values).FindAll(x => (0 == (x % 2)));
}}
public class OddGetter : Decoratable, ValueGetter {
	public OddGetter(ValueGetter getter) : base(getter) {}
	public List<int> Get(List<int> values) { return getter.Get(values).FindAll(x => (0 != (x % 2)));}
}
public class Multiples3Getter : Decoratable, ValueGetter {
	public Multiples3Getter(ValueGetter getter) : base(getter) {}
	public List<int> Get(List<int> values) { return getter.Get(values).FindAll(x => (0 == (x % 3))); }
}

public class Test
{
	public static void Main()
	{
		PlainGetter p = new PlainGetter();
		EvenGetter e = new EvenGetter(p);
		OddGetter o = new OddGetter(p);
		Multiples3Getter t = new Multiples3Getter(p);
		ValueGetter et = new Multiples3Getter(e);
		ValueGetter ot = new Multiples3Getter(o);
		
		List<int> list = new List<int> {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};
		p.Get(list).ForEach(x => System.Console.Write(x+",")); System.Console.WriteLine();
		e.Get(list).ForEach(x => System.Console.Write(x+",")); System.Console.WriteLine();
		o.Get(list).ForEach(x => System.Console.Write(x+",")); System.Console.WriteLine();
		t.Get(list).ForEach(x => System.Console.Write(x+",")); System.Console.WriteLine();
		et.Get(list).ForEach(x => System.Console.Write(x+",")); System.Console.WriteLine();
		ot.Get(list).ForEach(x => System.Console.Write(x+",")); System.Console.WriteLine();
	}
}