using System;

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

public class Program

{

    public static void Main()

    {

        string json = @"

        { 

            ""a"": 10,

            ""b"": ""foo"",

            ""c"": 30,

            ""d"": ""bar"",

        }";

​

        var stuff = JsonConvert.DeserializeObject<Stuff>(json);

​

        Console.WriteLine(stuff.A);

        Console.WriteLine(stuff.B);

        Console.WriteLine(stuff.Others["c"]);

        Console.WriteLine(stuff.Others["d"]);

    }

}

​

class Stuff 

{

    public int A { get; set; }

    public string B { get; set; }

    [JsonExtensionData]

    public JObject Others { get; set; }

}

​