-er c-- ccc cce cck cco ccr ccs ccu ce- cec cee cek ceo cer ces ceu ckc cko cks co- coc coe cok coo cor cos cou crc cre crk cro crr crs cru csc cse csk cso csr css csu cuc cue cuk cuo cur cus cuu ec- ecc ece eck eco ecr ecs ecu eec eee eek eeo eer ees ekc eke eko ekr eks eku eo- eoc eoe eok eoo eor eos eou erc ere erk ero err ers eru es- esc ese esk eso esr ess esu eu- euc eue eur eus kcc kce kck kcr kcs kcu ke- kec kee kek keo ker kes kkc kke kkk kkr kks kku koc koe kok koo kor kos kou krc krk kro krr krs kru ksc kse ksk kso ksr kss ksu kuc kue kuk kur kus kuu oc- occ ock oco ocr ocs ocu oec oee oeo oer oes okc oke okk oko okr oks oku oo- ooc ook ooo oor oos or- orc ore ork oro orr ors oru os- osc ose osk oso osr oss osu ou- ouc oue ouk ouo our ous rcc rce rco rcr rcs rcu re- rec ree rek reo rer res reu rkc rke rkk rko rks rku roc roe rok roo ror ros rou rrc rrk rrr rrs rru rsc rse rsk rso rsr rss rsu ruc rue ruk ruo rur rus ruu scc sce sck sco scr scs scu se- sec see sek seo ser ses seu sk- skc ske skk sko skr sks sku soc soe sok soo sor sos sou sr- src sre srk sro srr srs ss- ssc sse ssk sso ssr sss ssu suc sue suk suo sur sus suu ucc uce uck uco ucr ucs ucu uec uee uer ues ukc uke ukk ukr uku uoc uoe uok uoo uor uos ur- urc ure urk uro urr urs uru usc use usk uso usr uss usu uuc uue uur uus uuu