c-- ccc cck ccm cco ccr ckc ckm cko cmc cmk cmm cmo cmr co- coc cok com coo cor crc crk crm cro crr kcc kck kcm kcr kkc kkk kkm kkr kmc kmk kmm kmo koc kok kom koo kor krc krk kro krr m-o m-r mc- mcc mck mcm mco mcr mkc mkk mkm mko mkr mmc mmk mmm mmo mmr moc mok mom moo mor mrc mrk mrm mro mrr oc- occ ock ocm oco ocr okc okk oko okr om- omc omm omo omr oo- ooc ook oom ooo oor or- orc ork orm oro orr rcc rcm rco rcr rkc rkk rkm rko rmc rmm rmo rmr roc rok rom roo ror rrc rrk rrm rrr