-er c-- c-j ccc cce ccj cck cco ccr ce- cec cee cej cek ceo cer cjc cjk cjr ckc cko co- coc coe coj cok coo cor crc cre crj crk cro crr ec- ecc ece ecj eck eco ecr eec eee eek eeo eer ejc ejo ekc eke eko ekr eo- eoc eoe eok eoo eor erc ere erk ero err jcc jce jck jco jcr jec jee jej jek jeo jer jjc jjj jjk jjr jkk jko jkr joc joe joj jok joo jor jrc jrk jro jrr kcc kce kck kcr ke- kec kee kek keo ker kjc kje kjr kkc kke kkk kkr koc koe kok koo kor krc krk kro krr oc- occ ocj ock oco ocr oec oee oeo oer ojc oje ojo okc oke okj okk oko okr oo- ooc ook ooo oor or- orc ore ork oro orr rcc rce rcj rco rcr re- rec ree rek reo rer rjc rjk rjr rkc rke rkk rko roc roe roj rok roo ror rrc rrk rrr