using System;

using System.Linq;

using System.Collections.Generic;

using Newtonsoft.Json;

public class Program

{

    public static void Main()

    {

        string someJson = "{\"BTC\":{\"USD\":7358.8},\"ETH\":{\"USD\":402.78},\"LTC\":{\"USD\":125.37},\"DASH\":{\"USD\":335.73},\"XMR\":{\"USD\":187.2},\"NXT\":{\"USD\":0.1272},\"ZEC\":{\"USD\":204.82},\"XRP\":{\"USD\":0.5296},\"WAVES\":{\"USD\":4},\"BCH\":{\"USD\":705.74},\"EOS\":{\"USD\":5.89},\"XLM\":{\"USD\":0.229},\"ADA\":{\"USD\":0.1601},\"NEO\":{\"USD\":52.03},\"IOT\":{\"USD\":1.07}}";

        var coins = JsonConvert.DeserializeObject<Dictionary<string, object>>(someJson).Select(x => x.Key);

        foreach(var c in coins)

        {

            Console.WriteLine(c);

        }

    }

}