hero recruitment

using System;
using System.Linq;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using System.Runtime.InteropServices;
using System.Data;
using System.IO;
using System.Reflection.PortableExecutable;

namespace _02._Boss_Rush
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] command = Console.ReadLine().Split();

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

            while (command[0] != "End")
            {
                if (command[0] == "Enroll")
                {
                    if (magic.ContainsKey(command[1]))
                    {
                        Console.WriteLine($"{command[1]} is already enrolled.");
                    }
                    else
                    {
                        magic[command[1]] = new List<string>();
                    }
                }
                if (command[0] == "Learn")
                {
                    if (magic.ContainsKey(command[1]))
                    {
                        bool spellExist = false;
                        foreach (var item in magic)
                        {
                            if (item.Value.Contains(command[2]))
                            {
                                spellExist = true;
                            }
                        }

                        if (spellExist)
                        {
                            Console.WriteLine($"{command[1]} has already learnt {command[2]}.");
                        }
                        else
                        {
                            magic[command[1]].Add(command[2]);
                        }
                    }
                    else
                    {
                        Console.WriteLine($"{command[1]} doesn't exist.");
                    }
                }
                if (command[0] == "Unlearn")
                {
                    if (magic.ContainsKey(command[1]))
                    {
                        bool spellExist = false;
                        foreach (var item in magic)
                        {
                            if (item.Value.Contains(command[2]))
                            {
                                spellExist = true;
                            }
                        }

                        if (spellExist)
                        {
                            magic[command[1]].Remove(command[2]);
                        }
                        else
                        {
                            Console.WriteLine($"{command[1]} doesn't know {command[2]}.");
                        }
                    }
                    else
                    {
                        Console.WriteLine($"{command[1]} doesn't exist.");
                    }
                }

                command = Console.ReadLine().Split();
            }

            Console.WriteLine("Heroes:");
            foreach (var item in magic.OrderByDescending(x => x.Value.Count).ThenBy(x => x.Key))
            {
                Console.WriteLine($"== {item.Key}: {string.Join(", ", item.Value)}");
            }
        }
    }
}