World Tour [C#]

using System;

namespace WorldTour
{
    public class Program
    {
        public static void Main(string[] args)
        {
            string text = Console.ReadLine();

            string line = string.Empty;

            while (line != "Travel")
            {
                line = Console.ReadLine();

                string[] parts = line.Split(":", StringSplitOptions.RemoveEmptyEntries);

                string command = parts[0];

                if (command == "Add Stop")
                {
                    int idx = int.Parse(parts[1]);

                    if (idx >= 0 && idx < text.Length)
                    {
                        string substr = parts[2];
                        text = text.Insert(idx, substr);
                    }

                    Console.WriteLine(text);
                }
                else if (command == "Remove Stop")
                {
                    int startIdx = int.Parse(parts[1]);
                    int endIdx = int.Parse(parts[2]);

                    if (startIdx >= 0 && endIdx < text.Length)
                    {
                        text = text.Remove(startIdx, endIdx - startIdx + 1);
                    }

                    Console.WriteLine(text);
                }
                else if (command == "Switch")
                {
                    string oldText = parts[1];
                    string newText = parts[2];

                    if (text.Contains(oldText))
                    {
                        text = text.Replace(oldText, newText);
                    }

                    Console.WriteLine(text);
                }
            }

            Console.WriteLine($"Ready for world tour! Planned stops: {text}");
        }
    }
}