Roli 2 Dicts

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

namespace RoliTheCoder
{
    public class Roli
    {
        public static void Main(string[] args)
        {
            Dictionary<int, string> activitiesByEventName = new Dictionary<int, string>();
            Dictionary<int, List<string>> activitiesByParticipants = new Dictionary<int, List<string>>();

            ProcessInput(activitiesByEventName, activitiesByParticipants);
            PrintOutput(activitiesByEventName, activitiesByParticipants);

        }

        private static void PrintOutput(Dictionary<int, string> activitiesByEventName, Dictionary<int, List<string>> activitiesByParticipants)
        {
            foreach (KeyValuePair<int, List<string>> activity in activitiesByParticipants.OrderByDescending(ev => ev.Value.Count).ThenBy(ev => ev.Key))
            {
                Console.WriteLine("{0} - {1}", activitiesByEventName[activity.Key], activity.Value.Count);

                foreach (string participant in activity.Value.OrderBy(part => part))
                {
                    Console.WriteLine(participant);
                }
            }
        }

        private static void ProcessInput(Dictionary<int, string> activitiesByEventName, Dictionary<int, List<string>> activitiesByParticipants)
        {
            string command = Console.ReadLine();

            while (command != "Time for Code")
            {
                string[] commandInfo = command.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);

                int id = int.Parse(commandInfo[0]);
                string eventName = commandInfo[1];
                List<string> participants = new List<string>(commandInfo.Skip(2));

                if (eventName[0] != '#')
                {
                    command = Console.ReadLine();
                    continue;
                }

                eventName = eventName.Substring(1);

                if (activitiesByEventName.ContainsKey(id))
                {
                    if (activitiesByEventName[id] == eventName)
                    {
                        AddParticipants(activitiesByParticipants, participants, id);
                    }
                }
                else
                {
                    activitiesByEventName.Add(id, eventName);
                    activitiesByParticipants.Add(id, participants.Distinct().ToList());
                }

                command = Console.ReadLine();
            }
        }

        public static void AddParticipants(Dictionary<int, List<string>> activitiesByParticipants,
            List<string> newParticipants, int id)
        {
            foreach (string participant in newParticipants.Distinct())
            {
                if (!activitiesByParticipants[id].Contains(participant))
                {
                    activitiesByParticipants[id].Add(participant);
                }
            }
        }
    }
}