ddd dde ddf ddo dds ddt de- ded dee def deo des det dfd dfe dff dfo dfs dft dod doe dof doo dos dot dsd dse dsf dso dss dst dtd dte dtf dto dts dtt ed- edd ede edf edo eds edt eed eee eef eeo ees eet ef- efd efe eff efo efs eft eo- eod eoe eof eoo eos eot es- esd ese esf eso ess est etd ete etf eto ets ett fdd fde fdf fdo fds fdt fed fee fef feo fes fet ffd ffe fff ffo ffs fft foe fof foo fos fot fsd fse fsf fso fss fst ftd fte ftf fto fts ftt odd ode odf odo ods odt oed oee oef oeo oes oet of- ofd ofe off ofo ofs oft oo- ood oof ooo oos oot os- osd ose osf oso oss ost ot- otd ote otf oto ots ott sdd sde sdf sdo sds sdt se- sed see sef seo ses set sfd sfe sff sfo sfs sft sod soe sof soo sos sot ss- ssd sse ssf sso sss sst std ste stf sto sts stt tdd tde tdf tdo tds tdt te- ted tee tef teo tes tet tfd tfe tff tfo tfs tft to- tod toe tof too tos tot tsd tse tsf tso tss tst ttd tte ttf tto tts ttt