c-- ccc ccg cck cco ccr ccu cgc cgg cgo cgr cgu ckc cko co- coc cog cok coo cor cou crc crg crk cro crr cru cuc cug cuk cuo cur cuu gcc gcg gck gco gcr gcu ggc ggg ggo ggr ggu gko goc gog gok goo gor gou grc grg grk gro grr gru gu- guc gug guk guo gur guu kcc kcg kck kcr kcu kgc kgo kgu kkc kkk kkr kku koc kog kok koo kor kou krc krg krk kro krr kru kuc kug kuk kur kuu oc- occ ocg ock oco ocr ocu ogc ogg ogo okc okg okk oko okr oku oo- ooc oog ook ooo oor or- orc org ork oro orr oru ou- ouc ouk ouo our rcc rcg rco rcr rcu rgc rgg rgk rgo rgr rkc rkg rkk rko rku roc rog rok roo ror rou rrc rrg rrk rrr rru ruc rug ruk ruo rur ruu ucc ucg uck uco ucr ucu ugc ugg ugk ugo ugr ugu ukc ukk ukr uku uoc uog uok uoo uor ur- urc urg urk uro urr uru uuc uug uur uuu