3
3 3 3
+-+
| |
+-+
7 7 2
  +-+  
  | |  
+-+ +-+
|     |
+-+ +-+
  | |  
  +-+  
7 12 1
+----------+
|          |
| +----+   |
| |    |   |
| +---+|   |
|     |+---+
+-----+