using System;

using System.Text.RegularExpressions;

​

namespace HelloWorld

{

    public class Program

    {

        public static void Main(string[] args)

        {

            try

            {

                string regexPattern = @"\hel#lo\m";

                Regex regex = new Regex(regexPattern);

                string inputString = "hello world!";

                Match match = regex.Match(inputString);

                if (match.Success)

                {

                    Console.WriteLine("Match found.");

                }

                else

                {

                    Console.WriteLine("No match found.");

                }

            }

            catch (RegexMatchTimeoutException ex)

            {

                Console.WriteLine("Timeout Error: " + ex.Message);

            }

            catch (RegexParseException ex)

            {

                Console.WriteLine("Error in parsing regular expression: " + ex.Message);

            }

        }

    }

}