void binarySearch(User user, int begin, int end) {
        if (end != begin && flag) {
            binarySearch(user, begin, (int) (((long) end + begin) / 2));
            binarySearch(user, (int) (((long) end + begin) / 2) + 1, end);
        } else if (user.theNumberIs(end)) {
            answer = end;
            flag = false;
//            System.out.print(answer);
        }
    }