using System;

using System.Collections.Generic;

​

public static class Extensions 

{   

    public static IEnumerable<T> Where<T>(this IEnumerable<T> items, Func<T, bool> predicate) 

    {

            foreach(T item in items)

                if(predicate(item))

                yield return item;

    }

}

​

// Using deferred execution

​

public class Program

{

    public static void Main()

    {

        var inputs = new List<int>{1,4,2,3,7,6,12,44,23,29};

        var even =

            from a in inputs

            where a % 2 == 1

            select a;

        var odd = 

            from a in inputs

            where a % 2 != 1

            select a;

        var roll = even.GetEnumerator();

        while(roll.MoveNext())

            Console.WriteLine(roll.Current + " Even");

        var poll = odd.GetEnumerator();

        while(poll.MoveNext())

            Console.WriteLine(poll.Current + " Odd");

    }

}