using System;

using System.Collections.Generic;

using System.Collections.Concurrent;

public class Program

{

    public static void Main()

    {

        var dictionary = new ConcurrentDictionary<string, int>();

        var key = new string(new char[] { 'A', 'B' });

        var @value = 8;

        dictionary.TryAdd(key, @value);

        Console.WriteLine(dictionary[key]);

        var qu = new Queue<char>();

        qu.Enqueue('A');

        qu.Enqueue('B');

        key = new string(qu.ToArray());

        Console.WriteLine(dictionary[key]);

    }

}