Phonebook

using System;
using System.Linq;
using System.Collections.Generic;


namespace Dictionaries
{
    class Program
    {
        public static void Main(string[] args)
        {
            Dictionary<string, string> phoneDetails = new Dictionary<string, string>();

            List<string> commands = Console.ReadLine().Split(' ').ToList();
            string token = commands[0];

            while (token != "END")
            {
                switch (token)
                {
                    case "A":
                        string index = commands[1];
                        string entry = commands[2];
                        phoneDetails.Add(index, entry);
                        break;
                    case "S":
                        string searched = commands[1];
                        string result = null;
                        if (phoneDetails.TryGetValue(searched, out result))
                        {
                            Console.WriteLine("{0} -> {1}", searched, result);
                        }
                        else
                        {
                            Console.WriteLine("Contact {0} does not exist.", searched);
                        }
                        break;
                }

                commands = Console.ReadLine().Split(' ').ToList();
                token = commands[0];
            }
        }
    }
}