using System;

    using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var myList = new List<string>();

myList.Add("One");

myList.Add("Two");

var letters = "Oo";

var matches = myList.Where(x => letters.Any(y => x.Contains(y)));

        foreach(var a in matches)

        Console.WriteLine("Hello World"+a);

    }

}