-er c-- ccc cce ccf cco ccr ce- cec cee cef ceo cer cfc cfe cff cfo cfr co- coc coe cof coo cor crc cre crf cro crr ec- ecc ece ecf eco ecr eec eee eef eeo eer ef- efc efe eff efo efr eo- eoc eoe eof eoo eor erc ere erf ero err fcc fce fcf fco fcr fec fee fef feo fer ffc ffe fff ffo ffr foc foe fof foo for frc fre frf fro frr oc- occ ocf oco ocr oec oee oef oeo oer of- ofc ofe off ofo ofr oo- ooc oof ooo oor or- orc ore orf oro orr rcc rce rcf rco rcr re- rec ree ref reo rer rfc rfe rff rfo rfr roc roe rof roo ror rrc rrf rrr