c-- ccc cck cco ccr ccu ckc cko cky co- coc cok coo cor cou coy crc crk cro crr cru cry cuc cuk cuo cur cuu cuy cyc cyk cyo cyr kcc kck kcr kcu kkc kkk kkr kku kky koc kok koo kor kou koy krc krk kro krr kru kry kuc kuk kur kuu kuy kyc kyo kyr kyu oc- occ ock oco ocr ocu okc okk oko okr oku oo- ooc ook ooo oor or- orc ork oro orr oru ory ou- ouc ouk ouo our oyo rcc rco rcr rcu rkc rkk rko rku rky roc rok roo ror rou roy rrc rrk rrr rru ruc ruk ruo rur ruu ruy ry- ryc ryk ryo ryr ryu ryy ucc uck uco ucr ucu ukc ukk ukr uku uoc uok uoo uor ur- urc urk uro urr uru ury uuc uur uuu uyc uyo uyu ycc yco ycu ycy ykk yoc yok yoo yor you yoy yrc yro yru yuk yuo yur yuu yuy yyc yyu yyy