using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(string.Join(", ", GetDisjointedList(new[]{0, 1, 1, 1, 2, 2}, new[]{0, 0, 0, 1, 1})));

    }

    private static int[] GetDisjointedList(int[] a, int[] b)

    {

        var dict = new Dictionary<int, int>(){};

        foreach(var t in a)

        {

            if(!dict.ContainsKey(t))

            {

                dict[t] = 0;

            }

            dict[t]++;

        }

        foreach(var t in b)

        {

            if(!dict.ContainsKey(t))

            {

                dict[t] = 0;

            }

            dict[t]--;

        }

        var output = new List<int>();

        foreach(var d in dict)

        {

            for(var i = 0; i < Math.Abs(d.Value); i++)

            {

                output.Add(d.Key);

            }

        }

        return output.ToArray();

    }

}