**Java Solution **

public static int getTotalX(List<Integer> a, List<Integer> b) {

    /* Assuming the last value in 'a' is the maximum and
       the first value in 'b' is the minimum */

    int start = a.get(a.size()-1),end=b.get(0),count=0;

            for (int i = start; i <= end; i+=start) { 

                boolean trueForA = true, trueForB = true ;

                for (int num : a) {
                    if (i % num != 0) {
                        trueForA = false;
                        break;
                    }
                }

                for (int num : b) {
                    if(trueForA)
                        if (num % i != 0) {
                        trueForB = false;
                        break;
                    }
                  }


                if (trueForA &&  trueForB) {
                   count++;
                 }
         }
    return count;
}