using System;

using System.Collections.Generic;

using Newtonsoft.Json;

public class Program

{

    public static void Main()

    {

        string json = @"{""USD_PHP"":{""2016-12-31"":49.560001},""PHP_USD"":{""2016-12-31"":0.020178}}";

        var outer = JsonConvert.DeserializeObject<Dictionary<string, Dictionary<string, decimal>>>(json);

        foreach (var kvp in outer)

        {

            foreach (var kvp2 in kvp.Value)

            {

                Console.WriteLine(kvp.Key + "  " + kvp2.Key + "  " + kvp2.Value);

            }

        }   

    }

}