user logs

namespace nestedDictionaries
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;

    class Program
    {
        static void Main(string[] args)
        {

            SortedDictionary<string,Dictionary<string,int>>usersAndIps=new SortedDictionary<string, Dictionary<string, int>>();

            string input;

            while ((input=Console.ReadLine())!="end")
            {
                if (input == null) continue;
                string[] tokens = input.Split(new[]{'=',' '}, StringSplitOptions.RemoveEmptyEntries).ToArray();

                string ip = tokens[1];
                string user = tokens[5];

                if (!usersAndIps.ContainsKey(user))
                {
                    usersAndIps.Add(user,new Dictionary<string, int>());
                    usersAndIps[user].Add(ip,1);
                }
                else if(!usersAndIps[user].ContainsKey(ip))
                {
                    usersAndIps[user].Add(ip, 1);
                }
                else
                {
                    usersAndIps[user][ip] += 1;
                }
            }

            StringBuilder sb = new StringBuilder();

            foreach (var user in usersAndIps)
            {
                sb.AppendLine($"{user.Key}: ");
                int count = user.Value.Count;
                int current = 0;
                foreach (var ips in user.Value)
                {
                    current++;
                    string ip = current<count? string.Format("{0} => {1}, ", ips.Key, ips.Value)
                                             : string.Format("{0} => {1}.", ips.Key, ips.Value);
                    sb.Append(ip);
                }

                Console.WriteLine(sb.ToString());
                sb.Clear();
            }

        }
    }
}