Final Exam/On the Way to Annapurna

using System;
using System.Linq;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;

namespace fundamental14
{
    class MainClass
    {
        public static void Main()
        {

            Dictionary<string, List<string>> store = new Dictionary<string, List<string>>();

            string input = string.Empty;

            while((input = Console.ReadLine()) != "END")
            {
                string[] arry = input.Split("->").ToArray();
                string command = arry[0];
                string storeList = arry[1];

                if (command == "Add")
                {
                    List<string> items = arry[2].Split(",").ToList();

                    if(!store.ContainsKey(storeList))
                    {
                        store.Add(storeList, items);
                    }
                    else
                    {
                        foreach (var item in items)
                        {
                            store[storeList].Add(item);
                        }

                    }
                }
                else
                {
                    if(store.ContainsKey(storeList))
                    {
                        store.Remove(storeList);
                    }
                }
            }

            Console.WriteLine("Stores list:");

            foreach (var kvp in store.OrderByDescending(x => x.Value.Count).ThenByDescending(x => x.Key))
            {
                Console.WriteLine($"{kvp.Key}");
                foreach (var product in kvp.Value)
                {
                    Console.WriteLine($"<<{product}>>");
                }
            }
        }
    }
}