c-- ccc cch cck cco ccr ccs ch- chc chh chk cho chr chs ckc ckh cko cks co- coc coh cok coo cor cos crc crh crk cro crr crs csc csh csk cso csr css hcc hch hck hco hcr hcs hhc hhh hhk hho hhr hhs hkh hkk hko hkr hks hoc hoh hok hoo hor hos hr- hrc hrh hrk hro hrr hrs hsc hsh hsk hsr hss kcc kch kck kcr kcs khh khk kho khr khs kkc kkh kkk kkr kks koc koh kok koo kor kos krc krk kro krr krs ksc ksh ksk kso ksr kss oc- occ och ock oco ocr ocs ohc ohh oho ohr ohs okc okk oko okr oks oo- ooc ooh ook ooo oor oos or- orc orh ork oro orr ors os- osc osh osk oso osr oss rcc rch rco rcr rcs rh- rhc rhh rho rhr rhs rkc rkk rko rks roc roh rok roo ror ros rrc rrh rrk rrr rrs rsc rsh rsk rso rsr rss scc sch sck sco scr scs sh- shc shh shk sho shr shs sk- skc skh skk sko skr sks soc soh sok soo sor sos sr- src srh srk sro srr srs ss- ssc ssh ssk sso ssr sss