+----+-----+---+---------+---+----------+ 
||   |     |   |         |   |     |   || 
||S| | | | | | | | | |- -+ | | | | | | || 
||-+ + | +-+ | | | +-+ + +-+ | | +-+ | || 
||     |     | | |   |   |     |     | || 
|| ----+-----+ | | --+- -+ ----+-----+ || 
||          +--+ |       |          +--+| 
|| | + | -+    | | +---- | | + | -+    || 
|| |   |  +--+ | | |     | |   |  +--+ || 
|| +---+---+ | | | +-----+ +---+---+ | || 
||         |     |                 |   || 
|+---+---- +---+-+------ +---+---+ |---+| 
||   |     |   |         |   |     |   || 
|| | | | | | | | | | |- -+ | | | | | | || 
|+-+ | | +-+ | | | +-+ + +-+ | | +-+ | || 
||     |     | | |   |   |     |     | || 
|| ----+-----+ | | --+- -+ ----+-----+ || 
||          +--+ |       |          +--+| 
|| | + | -+    | | +---- | | + | -+    || 
|| |   |  +--+ | | |     | |   |  |+-+ || 
|| +---+---+ | | | +-----+ +---+--+| | || 
||        E|     |       |         |   || 
+----------------+-------+---------+----+