-er c-- ccc ccd cce ccm cco ccr cdc cdd cde cdm cdo cdr ce- cec ced cee cem ceo cer cmc cmd cme cmm cmo cmr co- coc cod coe com coo cor crc crd cre crm cro crr dcc dcd dce dcm dco dcr ddc ddd dde ddm ddo ddr de- dec ded dee dem deo der dmc dmd dme dmm dmo dmr doc dod doe dom doo dor drc drd dre drm dro drr ec- ecc ecd ece ecm eco ecr ed- edc edd ede edm edo edr eec eed eee eem eeo eer em- emc emd eme emm emo emr eo- eoc eod eoe eom eoo eor erc erd ere erm ero err m-o m-r mc- mcc mcd mce mcm mco mcr mdc mdd mde mdm mdo mdr mec med mee mem meo mer mmc mmd mme mmm mmo mmr moc mod moe mom moo mor mrc mrd mre mrm mro mrr oc- occ ocd ocm oco ocr odc odd ode odm odo odr oec oed oee oem oeo oer om- omc omd ome omm omo omr oo- ooc ood oom ooo oor or- orc ord ore orm oro orr rcc rcd rce rcm rco rcr rdc rdd rde rdm rdo rdr re- rec red ree rem reo rer rmc rmd rme rmm rmo rmr roc rod roe rom roo ror rrc rrd rrm rrr