using System;

using System.Text.RegularExpressions;

​

public class ExtractHyperlinks

{

    public static void Main(string[] args)

    {

        string input = "You are part of the back-end development team of the next Facebook. You are given a line of usernames, between one of the following symbols: space, “\\/”, “\\”, “(“, “)” . First you have to export all valid usernames. A valid username starts with a letter and can contain only letters, digits and “_”. It cannot be less than 3 or more than 25 symbols long. Your task is to sum the length of every 2 consecutive valid usernames and print on the console the 2 valid usernames with biggest sum of their lengths, each on a separate line. ";

        Regex rgx = new Regex(@"[^a-z]*");

        Match match = rgx.Match(input);

        while (match != Match.Empty)

        {

            Console.Write(match.Value);

            match = match.NextMatch();

        }

    }

}