-er -ic c-- ccc cce cci cck cco ccr ccs ce- cec cee cei cek ceo cer ces ci- cic cie cii cik cio cir cis ckc cki cko cks co- coc coe coi cok coo cor cos crc cre cri crk cro crr crs csc cse csi csk cso csr css ec- ecc ece eci eck eco ecr ecs eec eee eek eeo eer ees eic eie eii eik eio eir eis ekc eke eki eko ekr eks eo- eoc eoe eoi eok eoo eor eos erc ere eri erk ero err ers es- esc ese esi esk eso esr ess icc ice ici ick ico icr ics ie- iec iee iei iek ier ies iic iie iii iio iir iis ikc ike iki ikk iko ikr iks io- ioc ioe ioi ioo ior ios ir- irc ire iri irk iro irr irs is- isc ise isi isk iso isr iss kcc kce kci kck kcr kcs ke- kec kee kei kek keo ker kes kic kie kii kik kio kir kis kkc kke kki kkk kkr kks koc koe koi kok koo kor kos krc kri krk kro krr krs ksc kse ksi ksk kso ksr kss o-i oc- occ oci ock oco ocr ocs oec oee oei oeo oer oes oic oie oii oik oio oir ois okc oke oki okk oko okr oks oo- ooc ooi ook ooo oor oos or- orc ore ori ork oro orr ors os- osc ose osi osk oso osr oss rcc rce rci rco rcr rcs re- rec ree rei rek reo rer res ric rie rii rik rio rir ris rkc rke rkk rko rks roc roe roi rok roo ror ros rrc rri rrk rrr rrs rsc rse rsi rsk rso rsr rss scc sce sci sck sco scr scs se- sec see sei sek seo ser ses sic sie sii sik sio sir sis sk- skc ske ski skk sko skr sks soc soe soi sok soo sor sos sr- src sre sri srk sro srr srs ss- ssc sse ssi ssk sso ssr sss