ddd dde ddf ddi ddt ddx de- ded dee def dei det dex dfd dfe dff dfi dft dfx di- did die dif dii dit dix dtd dte dtf dti dtt dtx dxd dxi dxt dxx ed- edd ede edf edi edt edx eed eee eef eet eex ef- efd efe eff efi eft efx eid eie eif eii eit eix etd ete etf eti ett etx ex- exd exe exi ext exx fdd fde fdf fdi fdt fdx fed fee fef fei fet fex ffd ffe fff ffi fft ffx fid fie fif fii fit fix ftd fte ftf fti ftt ftx fxe fxi fxt fxx i-d i-f idd ide idf idi idt idx ie- ied iee ief iei iet iex ifd ife iff ifi ift ifx iid iie iif iii iit iix itd ite itf iti itt itx ixe ixi t-x tdd tde tdf tdi tdt tdx te- ted tee tef tei tet tex tfd tfe tff tfi tft tfx tid tie tif tii tit tix ttd tte ttf tti ttt ttx txe txf txi txt xde xdf xdi xdt xed xee xet xex xfe xft xfx xie xii xit xix xtf xti xtx xxi xxx