shopping list

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

namespace mid_exam
{
    class Program
    {
        static void Main(string[] args)
        {
            List<string> groceries = Console.ReadLine().Split("!").ToList();

            string command = Console.ReadLine();

            while (command != "Go Shopping!")
            {
                string[] shopping = command.Split().ToArray();


                    if (shopping[0] == "Urgent")
                    {
                        string product = shopping[1];

                        if (!(groceries.Contains(product)))
                        {
                            groceries.Insert(0, product);
                        }

                    }
                    else if (shopping[0] == "Unnecessary")
                    {
                        string product = shopping[1];

                        if (groceries.Contains(product))
                        {
                            groceries.Remove(product);
                        }
                    }
                    else if(shopping[0] == "Rearrange")
                    {
                        string product = shopping[1];

                        if (groceries.Contains(product))
                        {
                            int index = groceries.IndexOf(product);
                            groceries.RemoveAt(index);
                            groceries.Add(product);
                        }
                    }
                    else if (shopping[0] == "Correct")
                    {

                        string product = shopping[1];

                        if (groceries.Contains(product))
                        {
                            string newItem = shopping[2];
                            int index = groceries.IndexOf(product);
                            groceries.RemoveAt(index);
                            groceries.Insert(index, newItem);
                        }

                    }

                command = Console.ReadLine();
            }

            Console.WriteLine(string.Join(", ", groceries));

        }
    }
}