public static int getTotalX(List<Integer> a, List<Integer> b) {
    Integer start = Collections.max(a);
    Integer finish = Collections.max(b);
    int counter = 0;
    for (int i = start; i <= finish; i++) {
        final int j = i;
        int count1 = (int)a.stream().filter(element -> j % element == 0).count();
        int count2 = (int)b.stream().filter(element -> element % j == 0).count();
        if (count1 == a.size() && count2 == b.size()) {
            ++counter;
        }
    }
    return counter;
    }