c-- ccc cch cco ccs ccx ch- chc chh cho chs chx co- coc coh coo cos cox csc csh cso css csx cxc cxh cxo cxs cxx hcc hch hco hcs hhc hhh hho hhs hoc hoh hoo hos hox hsc hsh hss hsx hxc oc- occ och oco ocs ocx ohc ohh oho ohs oo- ooc ooh ooo oos oox os- osc osh oso oss osx ox- oxc oxo oxx scc sch sco scs scx sh- shc shh sho shs soc soh soo sos sox ss- ssc ssh sso sss ssx sxc sxs xch xcx xoc xoo xos xox xsc xss xxo xxx