---5-7-8-7-5---5----------------
-------------8------------------
--------------------------------
-----------------77-9-7-6-------
-----------------77-9-7-6-------
-----------------55-6-5-4-------

--5-7-8-7-5-8-5----------------
-------------------------------
-------------------------------
----------------777-8-9--------
----------------777-8-9--------
----------------555-6-7--------

---5-6-8-6-5---5------------------
-------------8--------------------
----------------------------------
----------------------------------
-----------------777-6-5----------
-----------------555-4-3----------