c-- ccc ccg cck cco ccr ccs cgc cgg cgo cgr cgs ckc cko cks co- coc cog cok coo cor cos crc crg crk cro crr crs csc csg csk cso csr css gcc gcg gck gco gcr gcs ggc ggg ggo ggr ggs gko gks goc gog gok goo gor gos grc grg grk gro grr grs gsc gsg gsk gso gsr gss kcc kcg kck kcr kcs kgc kgo kgs kkc kkk kkr kks koc kog kok koo kor kos krc krg krk kro krr krs ksc ksg ksk kso ksr kss oc- occ ocg ock oco ocr ocs ogc ogg ogo ogs okc okg okk oko okr oks oo- ooc oog ook ooo oor oos or- orc org ork oro orr ors os- osc osg osk oso osr oss rcc rcg rco rcr rcs rgc rgg rgk rgo rgr rgs rkc rkg rkk rko rks roc rog rok roo ror ros rrc rrg rrk rrr rrs rsc rsg rsk rso rsr rss scc scg sck sco scr scs sgc sgg sgk sgo sgr sgs sk- skc skg skk sko skr sks soc sog sok soo sor sos sr- src srg srk sro srr srs ss- ssc ssg ssk sso ssr sss