using System;

using System.Collections.Generic;

​

​

public class AAA

{

    public List<int> Id { get; set; }

}

​

public class BBB

{

    public int Id { get; set; }

    public string description {get; set; }

}

​

public class Program

{

    public static void Main()

    {

        AAA aaa = new AAA();

        aaa.Id = new List<int>();

        int k = 1;

        aaa.Id.Add(k);

        k = 3;

        aaa.Id.Add(k);

        k = 6;

        aaa.Id.Add(k);

        List<BBB> bbb = new List<BBB>();

        BBB b = new BBB();

        b.Id = 1;

        b.description = "ME";

        bbb.Add(b);

        BBB c = new BBB();

        c.Id = 2;

        c.description = "ME";

        bbb.Add(c);

        BBB d = new BBB();

        d.Id = 3;

        d.description = "WW";

        bbb.Add(d);

        BBB e = new BBB();

        e.Id = 6;

        e.description = "KK";

        bbb.Add(e);

        bbb.ForEach(i => Console.WriteLine("{0},{1}",i.Id, i.description ));

        var nowe = bbb.FindAll(x => x.description != "ME");

        nowe.ForEach(i => Console.WriteLine("{0},{1}",i.Id, i.description ));       

    }

}