Middle Ex/Treasure Hunt

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

namespace fundamental14
{
    class MainClass
    {
        public static void Main()
        {
            List<string> chest = Console.ReadLine().Split("|").ToList();
            string input = string.Empty;
            List<string> stolen = new List<string>();

            while ((input = Console.ReadLine()) != "Yohoho!")
            {
                List<string> commandArgs = input.Split().ToList();
                string command = commandArgs[0];

                switch (command)
                {
                    case "Loot":
                        string[] items = commandArgs.Skip(1).ToArray();
                        LootCHest(items, chest);
                        break;
                    case "Drop":
                        int index = int.Parse(commandArgs[1]);
                        DropChest(index, chest);
                        break;
                    case "Steal":
                        int count = int.Parse(commandArgs[1]);
                        StealChest(count, chest);
                        break;
                }
            }

            double average = GetAverageChest(chest);

            if (chest.Count != 0)
            {
                Console.WriteLine($"Average treasure gain: {average:f2} pirate credits.");
            }
            else
            {
                Console.WriteLine("Failed treasure hunt.");
            }

            //Console.WriteLine(string.Join(" ", chest));
        }

        private static double GetAverageChest(List<string> chest)
        {
            double sum = 0;
            foreach (var item in chest)
            {
                sum += item.Length;
            }
            double average = sum / chest.Count;
            return average;
        }

        private static void StealChest(int count, List<string> chest)
        {
            int index = chest.Count - count;
            string[] deletedItems = null;

            if (index >= 0)
            {
                deletedItems = chest.Skip(index).ToArray();
                chest.RemoveRange(index, count);
            }
            else
            {
                deletedItems = chest.ToArray();
                chest.Clear();
            }

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

        }

        private static void DropChest(int index, List<string> chest)
        {
            if (IsValidIndex(index, chest))
            {
                string item = chest[index];
                chest.RemoveAt(index);
                chest.Add(item);
            }
        }

        private static bool IsValidIndex(int index, List<string> list)
        {
            return index < list.Count && index >= 0;
        }

        private static void LootCHest(string[] items, List<string> chest)
        {
            foreach (var item in items)
            {
                if (!chest.Contains(item))
                {
                    chest.Insert(0, item);
                }

            }
        }
    }
}