06. Barcode Generator with int

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int firstNum = Integer.parseInt(scanner.nextLine());
        int secondNum = Integer.parseInt(scanner.nextLine());

        int fourthSymbolFirstNum = firstNum % 10;
        firstNum = firstNum / 10;
        int fourthSymbolSecondNum = secondNum % 10;
        secondNum = secondNum / 10;

        int thirdSymbolFirstNum = firstNum % 10;
        firstNum = firstNum / 10;
        int thirdSymbolSecondNum = secondNum % 10;
        secondNum = secondNum / 10;

        int secondSymbolFirstNum = firstNum % 10;
        firstNum = firstNum / 10;
        int secondSymbolSecondNum = secondNum % 10;
        secondNum = secondNum / 10;

        int firstSymbolFirstNum = firstNum % 10;
        firstNum = firstNum / 10;
        int firstSymbolSecondNum = secondNum % 10;
        secondNum = secondNum / 10;

        //2345
        //6789
        for (int i = firstSymbolFirstNum; i <= firstSymbolSecondNum; i++) {
            if (i % 2 == 0) continue;
            for (int j = secondSymbolFirstNum; j <= secondSymbolSecondNum; j++) {
                if (j % 2 == 0) continue;
                for (int k = thirdSymbolFirstNum; k <= thirdSymbolSecondNum; k++) {
                    if (k % 2 == 0) continue;
                    for (int l = fourthSymbolFirstNum; l <= fourthSymbolSecondNum; l++) {
                        if (l % 2 == 0) continue;

                        System.out.printf("%d%d%d%d ", i, j, k, l);
                    }
                }
            }
        }
    }
}