O2. Fancy Barcodes / FinalExam - O4

package FinalExam.O4;

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

public class O2FancyBarcodes {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = Integer.parseInt(scanner.nextLine());
        for (int i = 0; i < n; i++) {
            String input = scanner.nextLine();
            Matcher matcher = Pattern.compile("(@#+)([A-Z][A-Za-z0-9]{4,}[A-Z])(@#+)").matcher(input);
            if (matcher.find()) {
                Pattern patternDigit = Pattern.compile("\\d");
                matcher = patternDigit.matcher(input);
                String result = "";
                while (matcher.find()) {
                    result += matcher.group();
                }
                if (result.equals("")) {
                    result = "00";
                }
                System.out.println("Product group: " + result);

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