[Retros] Add units, 18th update (1PA)

[Mu-Tsun Tsai]

Dear retro friends,

Here's a 1PA design I came up a few days ago. I have tried to make it as 
economic as possible, but I think there still might be room for improvement. 
Any idea?

Diagram:
http://www.janko.at/Retros/d.php?ff=8/Pp6/1P6/2R4P/P1N5/Pk3P2/pP1P4/b1K5
(11+4)

Intended solution: +bPh6


Mu-Tsun