using System;

using System.Collections.Generic;

using System.Linq;

using System.Text.RegularExpressions;

​

public class Program

{

    public static void Main()

    {

        MarketIdentifiersMap.Where(m => m.Value == "ticketmaster").Select(m => m.Key).Dump();

        MarketIdentifiersMap.Where(m => m.Value == "mfx-nl").Select(m => m.Key).Dump();

    }

    public static IReadOnlyDictionary<string, string> MarketIdentifiersMap =>

        new Dictionary<string, string>

    {

        { "GB",  "ticketmaster" }, // UK - host

        { "IE",  "ticketmaster" }, // IE - host

        { "ND",  "ticketmaster" }, // Northern Ireland - host

        { "NL",  "mfx-nl" },       // Netherlands - microflex

    };

​

}