using System;

using System.Text.RegularExpressions;

​

public class Program

{

    public static void Main()

    {

        string pattern = @"l+";

        string input = "Hello World!";

        Regex regex = new Regex(pattern);

        var matches = regex.Matches(input);

        if (matches.Count == 0)

        {

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

        }

        else

        {

            Console.WriteLine($"{matches.Count} match found");

            foreach (Match m in matches)

            {

                Console.WriteLine(m);

            }

        }

    }

}