static L<Rect> ocr_mergeOverlappingY(L<Rect> l) {
  l = cloneList(l);
  bool change;
  do {
    change = false;
    for i over l:
      for (int j = i+1; j < l(l); j++)
        if (rectsOverlapY(l.get(i), l.get(j))) {
          l.set(i, mergeRects(l.get(i), l.get(j)));
          l.remove(j--);
          change = true;
        }
  } while (change);
  ret l;
}