Fancy

package Exam;

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 = "@[#]{1,}[A-Z]{1}[A-Za-z0-9]{4,}[A-Z]{1}@[#]{1,}";
        Pattern pattern = Pattern.compile(regex);

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

        for (int i = 0; i < numberOfProducts; i++) {
            String current = scanner.nextLine();
            Matcher matcher = pattern.matcher(current);
            if (matcher.find()) {
                StringBuilder nums = new StringBuilder();
                current.chars().filter(Character::isDigit).forEach(e -> {
                    nums.append(String.valueOf((char) e));
                });
                System.out.println("Product group: " + ((nums.toString().trim().isEmpty()) ? "00" : nums.toString()));
            } else {
                System.out.println("Invalid barcode");
            }
        }
    }
}