using System.IO;

using System;

using Newtonsoft.Json;

​

public class Program

{

    public static void Main()

    {

        var s = "{\"a\":[1,2,3]}";

        dynamic json = JsonConvert.DeserializeObject(s);

        var a = json.a.ToObject<int[]>();

        Console.WriteLine(a[0]);

        Console.WriteLine(a[1]);

        Console.WriteLine(a[2]);

    }

}