ddd dde ddf ddl ddx de- ded dee def del dex dfd dfe dff dfl dfx dl- dld dle dlf dll dlx dxd dxl dxx ed- edd ede edf edl edx eed eee eef eel eex ef- efd efe eff efl efx eld ele elf ell elx ex- exd exe exl exx fdd fde fdf fdl fdx fed fee fef fel fex ffd ffe fff ffl ffx fld fle flf fll flx fxe fxx ldd lde ldf ldl led lee lef lel lex lfd lfe lff lfl lfx lld lle llf lll lxd lxx xde xdf xed xee xel xex xfe xfl xfx xld xlf xxl xxx