using System;

using System.Collections.Generic;

using System.Linq;

using System.IO;

using System.Reflection;

using System.Runtime.CompilerServices;

public class Program

{

    public static void Main()

    {

        var l = new List<string> {"jack", "aaron", "abraham"};

        var m = new string[] {"denny", "aaron", "abraham", "michael"}.Select(n => new {Name = n}).ToList();

        var diff = l.Where(n => !m.Select(x => x.Name).Contains(n));

​

        Console.WriteLine(string.Join(", ", diff));

    }

}