-er c-- ccc cce ccf ccm cco ccr ce- cec cee cef cem ceo cer cfc cfe cff cfm cfo cfr cmc cme cmf cmm cmo cmr co- coc coe cof com coo cor crc cre crf crm cro crr ec- ecc ece ecf ecm eco ecr eec eee eef eem eeo eer ef- efc efe eff efm efo efr em- emc eme emf emm emo emr eo- eoc eoe eof eom eoo eor erc ere erf erm ero err fcc fce fcf fcm fco fcr fec fee fef fem feo fer ffc ffe fff ffm ffo ffr fmc fme fmf fmm fmo fmr foc foe fof fom foo for frc fre frf frm fro frr m-f m-o m-r mc- mcc mce mcf mcm mco mcr mec mee mef mem meo mer mfc mfe mff mfm mfo mfr mmc mme mmf mmm mmo mmr moc moe mof mom moo mor mrc mre mrf mrm mro mrr oc- occ ocf ocm oco ocr oec oee oef oem oeo oer of- ofc ofe off ofm ofo ofr om- omc ome omf omm omo omr oo- ooc oof oom ooo oor or- orc ore orf orm oro orr rcc rce rcf rcm rco rcr re- rec ree ref rem reo rer rfc rfe rff rfm rfo rfr rmc rme rmf rmm rmo rmr roc roe rof rom roo ror rrc rrf rrm rrr