42b 
 +-----------------+
8|             r   |
7|   h     c r d r |
6|   r X   c X   h |
5| d r           H |
4| D R e   E   M m |
3|   H r R D X r   |
2|   C R   R R C R |
1|           R     |
 +-----------------+
   a b c d e f g h
