SafeManipulationCorrected

/*
 * Created by SharpDevelop.
 * User: savina.ivancheva
 * Date: 18.08.2017
 * Time: 09:18
 *
 * To change this template use Tools | Options | Coding | Edit Standard Headers.
 */
using System;
using System.Linq;

namespace SafeManipulation
{
	class Program
	{
		public static void Main(string[] args)
		{
			var input = Console.ReadLine().Split(' ');
			var manipulatedArray = input;
			int lengthArr = manipulatedArray.Length;


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


			while (command[0] != "END")
			{
				string action = command[0];


				if (action == "Reverse")
				{
					manipulatedArray = manipulatedArray.Reverse().ToArray();
				}
				else if (action == "Distinct")
				{

					manipulatedArray = manipulatedArray.Distinct().ToArray();
					lengthArr = manipulatedArray.Count(s => s != null);

				}
				else if (action == "Replace")

				{
					int index = int.Parse(command[1]);
					string wordToChange = command[2];

					if (index > lengthArr-1 || (index < 0))
					{
						Console.WriteLine("Invalid input!");
					}
					else
					{
						manipulatedArray[index] = wordToChange;
					}
				}
				else
				{
					Console.WriteLine("Invalid input!");
				}
				command = Console.ReadLine().Split(' ').ToArray();
			}

			Console.WriteLine(String.Join(", ", manipulatedArray));

		}
	}
}