-er c-- ccc cce ccm cco ccp ccr ce- cec cee cem ceo cep cer cmc cme cmm cmo cmp cmr co- coc coe com coo cop cor cpc cpe cpm cpo cpp cpr crc cre crm cro crp crr ec- ecc ece ecm eco ecr eec eee eem eeo eep eer em- emc eme emm emo emp emr eo- eoc eoe eom eoo eop eor ep- epc epe epm epo epp epr erc ere erm ero erp err m-o m-r mc- mcc mce mcm mco mcp mcr mec mee mem meo mep mer mmc mme mmm mmo mmp mmr moc moe mom moo mop mor mpc mpe mpm mpo mpp mpr mrc mre mrm mro mrp mrr oc- occ ocm oco ocp ocr oec oee oem oeo oep oer om- omc ome omm omo omp omr oo- ooc oom ooo oop oor op- opc ope opm opo opp opr or- orc ore orm oro orp orr p-p pcc pce pcm pco pcp pcr pec pee pem peo pep per pmc pme pmm pmo pmp pmr poc poe pom poo pop por ppc ppe ppm ppo ppp ppr prc pre prm pro prp prr rcc rce rcm rco rcp rcr re- rec ree rem reo rep rer rmc rme rmm rmo rmp rmr roc roe rom roo rop ror rpc rpe rpm rpo rpp rpr rrc rrm rrp rrr