Companu Users

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

namespace P08.Company_Users
{
    class Program
    {
        static void Main(string[] args)
        {
            var companyInfo = new Dictionary<string, List<string>>();
            string cmd;
            while ((cmd = Console.ReadLine()) != "End")
            {
                string[] command = cmd.Split(" -> ").ToArray();
                string companyName = command[0];
                string ID = command[1];

                if (!companyInfo.ContainsKey(companyName))
                {
                    var IDnumber = new List<string>
                    {
                        ID
                    };
                    companyInfo.Add(companyName, IDnumber);
                }
                if (!companyInfo[companyName].Contains(ID))
                {
                    companyInfo[companyName].Add(ID);
                }
            }
            foreach (var item in companyInfo.OrderBy(x => x.Key))
            {
                Console.WriteLine($"{item.Key}");

                foreach (var number in item.Value)
                {
                    Console.WriteLine($"-- {number}");
                }
            }
        }
    }
}