c-- ccc ccg cco ccr ccs cgc cgg cgo cgr cgs co- coc cog coo cor cos crc crg cro crr crs csc csg cso csr css gcc gcg gco gcr gcs ggc ggg ggo ggr ggs goc gog goo gor gos grc grg gro grr grs gsc gsg gso gsr gss oc- occ ocg oco ocr ocs ogc ogg ogo ogs oo- ooc oog ooo oor oos or- orc org oro orr ors os- osc osg oso osr oss rcc rcg rco rcr rcs rgc rgg rgo rgr rgs roc rog roo ror ros rrc rrg rrr rrs rsc rsg rso rsr rss scc scg sco scr scs sgc sgg sgo sgr sgs soc sog soo sor sos sr- src srg sro srr srs ss- ssc ssg sso ssr sss