12b
 +-----------------+
8| r r   m r   r r |
7| r c r       d c |
6| D h   E d   h D |
5| R R e C H H   C |
4|     M           |
3|             R R |
2|     R     R     |
1| R       R       |
 +-----------------+
   a b c d e f g h