using System;
using System.Collections.Generic;
using System.Linq;

public class Test
{
	public static void Main()
	{
	    var oldList = new List<int>() { 1, 2, 3, 4, 5 };
            var newList = new List<int>() { 1, 2, 3, 6, 7 };

            var value = oldList.Except(newList);

            foreach (var i in value)
            {
                Console.WriteLine(i);
            }
	}
}