-er a-a a-i aaa aad aae aaf aag aai aar aax ad- ada add ade adf adg adi adr adx aea aed aee aef aeg aei aer aex af- afa afd afe aff afg afi afr afx ag- aga agd age agf agg agi agr agx ai- aia aid aie aif aig aii air aix ar- ara ard are arf arg ari arr arx ax- axa axe axi axr axx daa dad dae daf dag dai dar dax dda ddd dde ddf ddg ddi ddr ddx de- dea ded dee def deg dei der dex dfa dfd dfe dff dfg dfi dfr dfx dga dgd dge dgf dgg dgi dgr di- dia did die dif dig dii dir dix dra drd dre drg dri drr drx dxd dxi dxr dxx eaa ead eae eaf eag eai ear eax ed- eda edd ede edf edg edi edr edx eea eed eee eef eeg eer eex ef- efa efd efe eff efg efi efr efx ega egd ege egf egg egi egr egx eia eid eie eif eig eii eir eix era erd ere erf erg eri err ex- exa exd exe exi exr exx faa fad fae faf fag fai far fax fda fdd fde fdf fdg fdi fdr fdx fea fed fee fef feg fei fer fex ffa ffd ffe fff ffg ffi ffr ffx fga fgd fge fgf fgg fgi fgr fia fid fie fif fig fii fir fix fra frd fre frf frg fri frr fxe fxg fxi fxr fxx g-d gaa gad gae gaf gag gai gar gda gdd gde gdf gdi gdr gdx ge- gea ged gee gef geg gei ger gex gfa gfd gfe gff gfi gfr gfx gga ggd ggg ggi ggr gia gid gie gif gig gii gir gra grd gre grf grg gri grr grx gxa gxf i-d i-f ia- iaa iad iae iaf iag iai iar ida idd ide idf idg idi idr idx ie- iea ied iee ief ieg iei ier iex ifa ifd ife iff ifg ifi ifr ifx iga igd ige igf igg igi igr iia iid iie iif iii iir iix ir- ira ird ire irf irg iri irr irx ixe ixi ra- raa rad rae raf rag rai rar rax rda rdd rde rdf rdg rdi rdr rdx re- rea red ree ref reg rei rer rex rfa rfd rfe rff rfg rfi rfr rga rgd rge rgf rgg rgi rgr rgx ria rid rie rif rig rii rir rix rra rrd rrf rrg rri rrr rxr xaa xad xaf xag xar xda xde xdf xdi xdr xed xee xeg xer xex xfa xfe xfx xge xgi xia xie xii xix xrd xrf xrx xxi xxx