c-- ccc ccg cck cco ccr cgc cgg cgo cgr ckc cko co- coc cog cok coo cor crc crg crk cro crr gcc gcg gck gco gcr ggc ggg ggo ggr gko goc gog gok goo gor grc grg grk gro grr kcc kcg kck kcr kgc kgo kkc kkk kkr koc kog kok koo kor krc krg krk kro krr oc- occ ocg ock oco ocr ogc ogg ogo okc okg okk oko okr oo- ooc oog ook ooo oor or- orc org ork oro orr rcc rcg rco rcr rgc rgg rgk rgo rgr rkc rkg rkk rko roc rog rok roo ror rrc rrg rrk rrr