NumberRetriever.java

class NumberRetriever{

    public static ArrayList<Integer> getNumberFromString(String input) {
        ArrayList<Integer> ints = new ArrayList<>();
        for (char a : input.toCharArray()) {
            try {
                ints.add(Integer.parseInt(String.valueOf(a)));
            }catch (NumberFormatException ignored) { }
        }
        return ints;
    }

    public static int getResultFromNumber(ArrayList<Integer> numbers) {
        boolean isEven = numbers.get(numbers.size()-1) % 2 == 0;
        int result = isEven ? 1 : 0;
        for (int num: numbers) {
            if (isEven) result *= num;
            else result += num;
        }
        return result;
    }

    public static void main(String[]args){
        ArrayList<Integer> numberList = getNumberFromString("a6s.,<Mv3d4_34(()2^&24!5");
        int result = getResultFromNumber(numberList);
        System.out.println(numberList);
        System.out.println(result);
    }
}