FancyBarcodes

import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class FancyBarcodes {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String regex = "^(@#+)(?<barcode>[A-Z][A-Za-z\\d]{4,}[A-Z])(@#+)$";
        Pattern pattern = Pattern.compile(regex);
        Pattern digits = Pattern.compile("(?<productGroup>[\\d]+)");

        int n = Integer.parseInt(scanner.nextLine());

        for (int i = 0; i < n; i++) {
            String input = scanner.nextLine();
            Matcher matcher = pattern.matcher(input);

            if (matcher.find()) {
                String barcode = matcher.group("barcode");
                Matcher digitMatcher = digits.matcher(barcode);

                if (digitMatcher.find()) {
                    String productGroup = barcode.replaceAll("[@#A-Za-z]+", "");
                    System.out.println(String.format("Product group: %s", productGroup));
                } else {
                    System.out.println("Product group: 00");
                }

            } else {
                System.out.println("Invalid barcode");
            }
        }
    }
}