    .----.        .----.
   /      \      /      \            .-----+-----+-----.
  +        +----+        +----.      |     |     |     |          .-----+-----+-----+-----+
   \      /      \      /      \     |     |     |     |         /     /     /     /     /
    +----+   B    +----+        +    +-----+-----+-----+        +-----+-----+-----+-----+
   /      \      /      \      /     |     |     |     |       /     /     /     /     /
  +   A    +----+        +----+      |     |  B  |     |      +-----+-----+-----+-----+
   \      /      \      /      \     +-----+-----+-----+     /     /  A  /  B  /     /
    '----+        +----+        +    |     |     |     |    +-----+-----+-----+-----+
          \      /      \      /     |  A  |     |     |   /     /     /     /     /
           '----'        '----'      '-----+-----+-----'  '-----+-----+-----+-----+

