-er ddd dde ddm ddo ddr de- ded dee dem deo der dmd dme dmm dmo dmr dod doe dom doo dor drd dre drm dro drr ed- edd ede edm edo edr eed eee eem eeo eer em- emd eme emm emo emr eo- eod eoe eom eoo eor erd ere erm ero err m-o m-r mdd mde mdm mdo mdr med mee mem meo mer mmd mme mmm mmo mmr mod moe mom moo mor mrd mre mrm mro mrr odd ode odm odo odr oed oee oem oeo oer om- omd ome omm omo omr oo- ood oom ooo oor or- ord ore orm oro orr rdd rde rdm rdo rdr re- red ree rem reo rer rmd rme rmm rmo rmr rod roe rom roo ror rrd rrm rrr