-er -ic c-- ccc cce cci cck cco ccr ce- cec cee cei cek ceo cer ci- cic cie cii cik cio cir ckc cki cko co- coc coe coi cok coo cor crc cre cri crk cro crr ec- ecc ece eci eck eco ecr eec eee eek eeo eer eic eie eii eik eio eir ekc eke eki eko ekr eo- eoc eoe eoi eok eoo eor erc ere eri erk ero err icc ice ici ick ico icr ie- iec iee iei iek ier iic iie iii iio iir ikc ike iki ikk iko ikr io- ioc ioe ioi ioo ior ir- irc ire iri irk iro irr kcc kce kci kck kcr ke- kec kee kei kek keo ker kic kie kii kik kio kir kkc kke kki kkk kkr koc koe koi kok koo kor krc kri krk kro krr o-i oc- occ oci ock oco ocr oec oee oei oeo oer oic oie oii oik oio oir okc oke oki okk oko okr oo- ooc ooi ook ooo oor or- orc ore ori ork oro orr rcc rce rci rco rcr re- rec ree rei rek reo rer ric rie rii rik rio rir rkc rke rkk rko roc roe roi rok roo ror rrc rri rrk rrr