using System;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        string command = "/brush on 5,5,5 15";

        string[] parts = command.Split(new string[] { " " }, StringSplitOptions.RemoveEmptyEntries);

        string[] args = parts.Skip(1).ToArray();

         if (args.Length < 1)

         {

             Console.WriteLine("ERROR: Command usage /brush ...");

             return;

         }

        if (args.Length > 0 && args.Length < 4)

            Console.WriteLine("Command Run: '" + command + "'");

        else

            Console.WriteLine("Invalid: '" + command + "'");

    }

}