-er ddd dde ddf ddm ddn ddr ddx de- ded dee def dem den der dex dfd dfe dff dfm dfn dfr dfx dmd dme dmf dmm dmn dmr dmx dnd dne dnf dnm dnn dnr drd dre drm drn drr drx dxd dxn dxr dxx ed- edd ede edf edm edn edr edx eed eee eef eem een eer eex ef- efd efe eff efm efr efx em- emd eme emf emm emn emr emx en- end ene enf enm enn enr erd ere erf erm ern err ex- exd exe exr exx fdd fde fdf fdm fdn fdr fdx fed fee fef fem fen fer fex ffd ffe fff ffm ffn ffr ffx fmd fme fmf fmm fmn fmr fmx fnd fne fnf fnm fnn fnr fnx frd fre frf frm frn frr fxe fxm fxr fxx m-f m-r mdd mde mdf mdm mdn mdr mdx med mee mef mem men mer mex mfd mfe mff mfm mfn mfr mmd mme mmf mmm mmn mmr mmx mne mnf mnm mnn mnr mrd mre mrf mrm mrn mrr mrx mxd mxn mxr ndd nde ndf ndm ndn ndr ne- ned nee nef nem nen ner nex nfd nfe nff nfn nfr nmd nme nmm nmn nmr nne nnf nnm nnn nrd nre nrf nrm nrn nrr nrx nxd rdd rde rdf rdm rdn rdr rdx re- red ree ref rem ren rer rex rfd rfe rff rfm rfn rfr rmd rme rmf rmm rmn rmr rmx rnd rnm rnn rnr rrd rrf rrm rrn rrr rxr xde xdf xdm xdr xed xee xem xen xer xex xfe xfm xfn xfx xmd xmf xmm xmr xmx xrd xrf xrx xxx