( shape(south, any 51xx + any 6xxx + any 7xxx + any 8xxx)
  or
  shape(north, any 51xx + any 6xxx + any 7xxx + any 8xxx)
)
and
hcp(west)+hcp(east)<28
and
(
  (shape(west, any 4333 + any 4432 + any 5332) 
   and hcp(west)>14
   and hcp(west)<=17 
  )
  or
  (shape(east, any 4333 + any 4432 + any 5332) 
   and hcp(east)>14
   and hcp(east)<=17 
  )
)