fancy barcodes

using System;
using System.Linq;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using System.Runtime.InteropServices;

namespace _02._Boss_Rush
{
    class Program
    {
        static void Main(string[] args)
        {
            Regex regex = new Regex(@"^[@][#]+(?<barcode>[A-Z][a-zA-Z0-9]{4,}[A-Z])[@][#]+$");

            int times = int.Parse(Console.ReadLine());

            //Dictionary<string, string> items = new Dictionary<string, string>();



            for (int i = 0; i < times; i++)
            {
                string input = Console.ReadLine();

                Match match = regex.Match(input);

                string sticker = "";

                if (match.Success)
                {
                    string barcode = match.Groups["barcode"].Value;

                    Regex digit = new Regex(@"[0-9]");

                    MatchCollection number = digit.Matches(barcode);

                    foreach (Match item in number)
                    {
                        //items[barcode] += item;
                        sticker += item.Value;
                    }

                    if (number.Count == 0)
                    {
                        // items[barcode] = "00";
                        sticker = "00";
                    }

                    Console.WriteLine($"Product group: {sticker}");
                }
                else
                {
                    Console.WriteLine("Invalid barcode");
                }
            }
        }
    }
}