03. Inventory

using System;
using System.Collections.Generic;

namespace Inventory
{
    class Program
    {
        static void Main(string[] args)
        {
            var collectedItems = Console.ReadLine().Split(", ").ToList();

            string commands;

            while ((commands = Console.ReadLine()) != "Craft!")
            {
                var tokens = commands.Split(" - ");
                string command = tokens[0], item = tokens[1];
                if (command == "Collect")
                {
                    if (!collectedItems.Contains(item))
                    {
                        collectedItems.Add(item);
                    }
                }
                else if (command == "Drop")
                {
                    if (collectedItems.Contains(item))
                    {
                        collectedItems.Remove(item);
                    }
                }
                else if (command == "Combine Items")
                {
                    var oldNewItems = item.Split(':');
                    string oldItem = oldNewItems[0], newItem = oldNewItems[1];
                    if (collectedItems.Contains(oldItem))
                    {
                        collectedItems.Insert(collectedItems.IndexOf(oldItem) + 1, newItem);
                    }
                }
                else
                {
                    if (collectedItems.Contains(item))
                    {
                        collectedItems.Remove(item);
                        collectedItems.Add(item);
                    }
                }
            }
            Console.WriteLine(String.Join(", ", collectedItems));
        }
    }
}