using System;

using System.Collections.Generic;

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

public class Program

{

    public class RootObject

    {

        public string key1 { get; set; }

        public string key2 { get; set; }

        public Dictionary<string, int> longlist { get; set; }

    }

    public static void Main()

    {       

        var r = @"{

                    ""key1"": ""value1"",

                    ""key2"": ""value2"",

                    ""longlist"": {

                        ""6060"": 123,

                        ""6061"": 664,

                        ""6200"": 43

                    }

                }";

        JObject jsonResponse = JObject.Parse(r);

        JObject objResponse = (JObject)jsonResponse["longlist"];

        RootObject _Data = Newtonsoft.Json.JsonConvert.DeserializeObject<RootObject>(jsonResponse.ToString());

        foreach (KeyValuePair<string, int> kvp in _Data.longlist)

        {

            Console.WriteLine(string.Format("Key: {0} Value: {1}", kvp.Key, kvp.Value));

        }

    }

}