-er ddd dde ddf ddm ddr de- ded dee def dem der dfd dfe dff dfm dfr dmd dme dmf dmm dmr drd dre drm drr ed- edd ede edf edm edr eed eee eef eem eer ef- efd efe eff efm efr em- emd eme emf emm emr erd ere erf erm err fdd fde fdf fdm fdr fed fee fef fem fer ffd ffe fff ffm ffr fmd fme fmf fmm fmr frd fre frf frm frr m-f m-r mdd mde mdf mdm mdr med mee mef mem mer mfd mfe mff mfm mfr mmd mme mmf mmm mmr mrd mre mrf mrm mrr rdd rde rdf rdm rdr re- red ree ref rem rer rfd rfe rff rfm rfr rmd rme rmf rmm rmr rrd rrf rrm rrr