Matched and unmatched elements from 2 lists , C#

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//Rextester.Program.Main is the entry point for your code. Don't change it.
//Compiler version 4.0.30319.17929 for Microsoft (R) .NET Framework 4.5

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace Rextester
{
    public class Privileges 
    {
        public int UserId {set;get;}
        public string FormName {set;get;}
        public string CompName {set;get;}
        public int Privilege {set;get;}
    }
    public class Program
    {
        public static void Main(string[] args)
        {
            List<Privileges> list1 = new List<Privileges>(){
                new Privileges(){UserId= 1,FormName="Form1",CompName="Button1",Privilege=2},
                new Privileges(){UserId= 2,FormName="Form1",CompName="Button3",Privilege=3},
                new Privileges(){UserId= 3,FormName="Form2",CompName="Button2",Privilege=2}
            };
            
            List<Privileges> list2 = new List<Privileges>(){
                new Privileges(){UserId= 5,FormName="Form1",CompName="Button1",Privilege=2},
                new Privileges(){UserId= 2,FormName="Form1",CompName="Button3",Privilege=4},
                new Privileges(){UserId= 4,FormName="Form2",CompName="Button2",Privilege=3}
            };
            
            var listMatched = GetMatchedElement(list1,list2);
            Console.WriteLine("listMatched = " +listMatched.Count);
            
            var listUnMatchedElementFrom1 = GetUnMatchedElementFromList1(list1,list2);
            Console.WriteLine("listUnMatchedElementFrom1 = " + listUnMatchedElementFrom1.Count);
            
            var listUnMatchedElementFrom2 = GetUnMatchedElementFromList2(list1,list2);
            Console.WriteLine("listUnMatchedElementFrom2 = " + listUnMatchedElementFrom2.Count);
        }
        private static List<Privileges> GetMatchedElement(List<Privileges> list1,List<Privileges> list2)
        {
            var list = (
                from l1 in list1 
                join l2 in list2 
                on new {l1.UserId,l1.FormName,l1.CompName}
                equals new {l2.UserId,l2.FormName,l2.CompName}
                select new Privileges (){
                    UserId = l1.UserId,
                    FormName = l1.FormName,
                    CompName = l1.CompName,
                    Privilege = 0}).ToList();
            return list;
        }
        
        private static List<Privileges> GetUnMatchedElementFromList1(List<Privileges> list1,List<Privileges> list2)
        {
             List<Privileges> list =  new List<Privileges>();
            return list;
        }
        
        private static List<Privileges> GetUnMatchedElementFromList2(List<Privileges> list1,List<Privileges> list2)
        {
             List<Privileges> list =  new List<Privileges>();
            return list;
        }
    }
}

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Compilation time: 0,14 sec, absolute running time: 0,11 sec, cpu time: 0,09 sec, average memory usage: 15 Mb, average nr of threads: 3