softuni parking

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.CSharp;


namespace Order_By_Age
{
    class Program
    {
        static void Main(string[] args)
        {
            int times = int.Parse(Console.ReadLine());

            Dictionary<string, string> list = new Dictionary<string, string>();

            for (int i = 0; i < times; i++)
            {
                string[] command = Console.ReadLine().Split().ToArray();

                if (command[0] == "register")
                {
                    if (list.ContainsKey(command[1]))
                    {
                        Console.WriteLine($"ERROR: already registered with plate number {command[2]}");
                    }
                    else
                    {
                        list.Add(command[1], command[2]);
                        Console.WriteLine($"{command[1]} registered {command[2]} successfully");
                    }
                }
                if (command[0] == "unregister")
                {
                    if (list.ContainsKey(command[1]))
                    {
                        list.Remove(command[1]);
                        Console.WriteLine($"{command[1]} unregistered successfully");
                    }
                    else
                    {
                        Console.WriteLine($"ERROR: user {command[1]} not found");
                    }
                }
            }

            foreach (var item in list)
            {
                Console.WriteLine($"{item.Key} => {item.Value}");
            }
        }
    }
}