-----------------12--17--12------------------------
--------------13------------13---------------------
-----------14------------------14-----------------14
--------14------------------------14------------14-
--12-15------------------------------15--12--15-----
--------------------------------------------------    etc...
  n  l  n  n  n  n   l   l  v  v  v  v   l   n  n  n


n= pua para abajo
l= ligado
v= pua para arriba