using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        Dictionary<int[], string> worldMap = new Dictionary<int[], string>();

        for (int x = 0; x <= 10; x++)

        {

            for (int y = 0; y <= 10; y++)

            {

                int[] cords = new int[] { x, y };

                worldMap.Add(cords, String.Format("empty{0}_{1}", x, y));

            }

        }

        // This should have 121 coordinates from (0, 0) to (10, 10)

        List<int[]> coords = worldMap.Keys.ToList();

        Console.WriteLine(worldMap[coords[21]]);

    }

}