softubi course planning

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

namespace exampreparation
{
    class exam
    {
        static void Main(string[] args)
        {
            List<string> schedule = Console.ReadLine().Split(", ").ToList();

            string[] command = Console.ReadLine().Split(':').ToArray();

            while (command[0] != "course start")
            {
                if (command[0] == "Add")
                {
                    if (!schedule.Contains(command[1]))
                    {
                        schedule.Add(command[1]);
                    }
                }
                if (command[0] == "Insert")
                {
                    int index = int.Parse(command[2]);

                    if (!schedule.Contains(command[1]))
                    {
                        schedule.Insert(index, command[1]);
                    }
                }
                if (command[0] == "Remove")
                {
                    if (schedule.Contains(command[1]))
                    {
                        schedule.Remove(command[1]);

                        if (schedule.Contains($"{command[1]}-Exercise"))
                        {
                            schedule.Remove($"{command[1]}-Exercise");
                        }

                    }
                    if (schedule.Contains($"{command[1]}-Exercise"))
                    {
                        schedule.Remove($"{command[1]}-Exercise");
                    }
                }
                if (command[0] == "Swap")
                {
                    if ((schedule.Contains(command[1]) && schedule.Contains(command[2])))
                    {
                        int index1 = schedule.IndexOf(command[1]);
                        int index2 = schedule.IndexOf(command[2]);

                        schedule[index1] = command[2];
                        schedule[index2] = command[1];

                        if (schedule.Contains($"{command[1]}-Exercise") && schedule.Contains($"{command[2]}-Exercise"))
                        {
                            if (index1 + 1 < schedule.Count && index2 + 1 < schedule.Count)
                            {
                                int indEx1 = schedule.IndexOf($"{command[2]}-Exercise");
                                schedule.RemoveAt(indEx1);
                                int indEx2 = schedule.IndexOf($"{command[1]}-Exercise");
                                schedule.RemoveAt(indEx2);
                                schedule.Insert(index1 + 1, $"{command[2]}-Exercise");
                                schedule.Insert(index2 + 1, $"{command[1]}-Exercise");
                            }
                        }
                        else if (schedule.Contains($"{command[1]}-Exercise"))
                        {
                            if (index2 + 1 < schedule.Count)
                            {
                                int indEx = schedule.IndexOf($"{command[1]}-Exercise");
                                schedule.RemoveAt(indEx);
                                schedule.Insert(index2 + 1, $"{command[1]}-Exercise");
                            }
                        }
                        else if (schedule.Contains($"{command[2]}-Exercise"))
                        {
                            if (index1 + 1 < schedule.Count)
                            {
                                int indEx = schedule.IndexOf($"{command[2]}-Exercise");
                                schedule.RemoveAt(indEx);
                                schedule.Insert(index1 + 1, $"{command[2]}-Exercise");

                            }
                        }
                    }
                }
                if (command[0] == "Exercise")
                {
                    string exercise = command[1] + '-' + "Exercise";
                    if (schedule.Contains(command[1]) && (!schedule.Contains(command[0])))
                    {
                        int index = schedule.IndexOf(command[1]) + 1;
                        schedule.Insert(index, exercise);
                    }
                    else if (!(schedule.Contains(command[0]) && schedule.Contains(command[1])))
                    {
                        schedule.Add(command[1]);
                        schedule.Add(exercise);
                    }
                }

                command = Console.ReadLine().Split(':').ToArray();
            }

            for (int i = 0; i < schedule.Count; i++)
            {
                Console.WriteLine($"{i + 1}.{schedule[i]}");
            }
        }
    }
}