a-a a-b a-t aaa aab aad aae aas aat aax ab- aba abb abd abe abs abt abx ad- ada adb add ade ads adt adx aea aeb aed aee aes aet aex as- asa asb asd ase ass ast asx at- ata atb atd ate ats att atx ax- axa axe axs axt axx baa bab bad bae bas bat bax bba bbb bbd bbe bbs bbt bbx bda bdb bdd bde bds bdt bdx be- bea beb bed bee bes bet bex bsa bsb bsd bse bss bst bsx bta btb btd bte bts btt btx bxb bxd bxx daa dab dad dae das dat dax dba dbb dbd dbe dbs dbt dbx dda ddb ddd dde dds ddt ddx de- dea deb ded dee des det dex dsa dsb dsd dse dss dst dsx dta dtb dtd dte dts dtt dtx dxd dxs dxt dxx eaa eab ead eae eas eat eax eba ebb ebd ebe ebs ebt ebx ed- eda edb edd ede eds edt edx eea eeb eed eee ees eet eex es- esa esb esd ese ess est esx eta etb etd ete ets ett etx ex- exa exd exe exs ext exx saa sab sad sae sas sat sax sba sbb sbd sbe sbs sbt sbx sda sdb sdd sde sds sdt se- sea seb sed see ses set sex ss- ssa ssb ssd sse sss sst ssx sta stb std ste sts stt stx sxs sxt t-x taa tab tad tae tas tat tax tba tbb tbd tbe tbs tbt tda tdb tdd tde tds tdt tdx te- tea teb ted tee tes tet tex tsa tsb tsd tse tss tst tsx tta ttb ttd tte tts ttt ttx txe txs txt xaa xad xas xat xbe xbx xda xdb xde xds xdt xed xee xes xet xex xsa xsb xss xst xts xtx xxx