Valid Usernames

/* 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.
 * The usernames should start with a letter and can contain only letters, digits and “_”. The username cannot be less than 3 or more than 25 symbols long.
 * Print at the console the 2 consecutive valid usernames with the biggest sum of their lengths each on a separate line. If there are 2 or more couples of usernames with the same sum of their lengths, print he left most. */

namespace _05.ValidUsernames
{
    using System;
    using System.Text.RegularExpressions;

    class ValidUsernames
    {
        static void Main(string[] args)
        {
            string text = Console.ReadLine();
            const string pattern = @"\b[A-Za-z]\w{2,24}\b";
            MatchCollection matches = Regex.Matches(text, pattern);

            int start = 0;
            int maxLength = 0;
            for (int i = 0; i + 1 < matches.Count; i++)
            {
                int length = matches[i].Length + matches[i + 1].Length;
                if (length > maxLength)
                {
                    maxLength = length;
                    start = i;
                }
            }

            for (int j = start; j < start + 2; j++)
            {
                Console.WriteLine(matches[j]);
            }
        }
    }
}