a-a a-b a-t aaa aab aad aae aas aat ab- aba abb abd abe abs abt ad- ada adb add ade ads adt aea aeb aed aee aes aet as- asa asb asd ase ass ast at- ata atb atd ate ats att baa bab bad bae bas bat bba bbb bbd bbe bbs bbt bda bdb bdd bde bds bdt be- bea beb bed bee bes bet bsa bsb bsd bse bss bst bta btb btd bte bts btt daa dab dad dae das dat dba dbb dbd dbe dbs dbt dda ddb ddd dde dds ddt de- dea deb ded dee des det dsa dsb dsd dse dss dst dta dtb dtd dte dts dtt eaa eab ead eae eas eat eba ebb ebd ebe ebs ebt ed- eda edb edd ede eds edt eea eeb eed eee ees eet es- esa esb esd ese ess est eta etb etd ete ets ett saa sab sad sae sas sat sba sbb sbd sbe sbs sbt sda sdb sdd sde sds sdt se- sea seb sed see ses set ss- ssa ssb ssd sse sss sst sta stb std ste sts stt taa tab tad tae tas tat tba tbb tbd tbe tbs tbt tda tdb tdd tde tds tdt te- tea teb ted tee tes tet tsa tsb tsd tse tss tst tta ttb ttd tte tts ttt