using System;

using System.Collections.Generic;

using Newtonsoft.Json;

public class Program

{

    public static void Main()

    {

        var Properties = new List<KeyValuePair<string, string>>();

        Properties.Add(JsonConvert.DeserializeObject<KeyValuePair<string, string>>("{\"key\":\"hello\"}"));

        Properties.Add(new KeyValuePair<string, string>{});

        Console.WriteLine("0 key: " + Properties[0].Key);

        Console.WriteLine("0 value: " + Properties[0].Value);

        Console.WriteLine("1 key: " + Properties[1].Key);

        Console.WriteLine("1 value: " + Properties[1].Value);

        Console.WriteLine("Hello World");

    }

}