-er ddd dde ddf ddm ddo ddr de- ded dee def dem deo der dfd dfe dff dfm dfo dfr dmd dme dmf dmm dmo dmr dod doe dof dom doo dor drd dre drm dro drr ed- edd ede edf edm edo edr eed eee eef eem eeo eer ef- efd efe eff efm efo efr em- emd eme emf emm emo emr eo- eod eoe eof eom eoo eor erd ere erf erm ero err fdd fde fdf fdm fdo fdr fed fee fef fem feo fer ffd ffe fff ffm ffo ffr fmd fme fmf fmm fmo fmr foe fof fom foo for frd fre frf frm fro frr m-f m-o m-r mdd mde mdf mdm mdo mdr med mee mef mem meo mer mfd mfe mff mfm mfo mfr mmd mme mmf mmm mmo mmr mod moe mof mom moo mor mrd mre mrf mrm mro mrr odd ode odf odm odo odr oed oee oef oem oeo oer of- ofd ofe off ofm ofo ofr om- omd ome omf omm omo omr oo- ood oof oom ooo oor or- ord ore orf orm oro orr rdd rde rdf rdm rdo rdr re- red ree ref rem reo rer rfd rfe rff rfm rfo rfr rmd rme rmf rmm rmo rmr rod roe rof rom roo ror rrd rrf rrm rrr