a-a a-b a-t aaa aab aad aae aao aas aat aax ab- aba abb abd abe abo abs abt abx ad- ada adb add ade ado ads adt adx aea aeb aed aee aeo aes aet aex aoa aob aod aoe aoo aos aot aox as- asa asb asd ase aso ass ast asx at- ata atb atd ate ato ats att atx ax- axa axe axo axs axt axx baa bab bad bae bao bas bat bax bba bbb bbd bbe bbo bbs bbt bbx bda bdb bdd bde bdo bds bdt bdx be- bea beb bed bee beo bes bet bex boa bob bod boe boo bos bot box bsa bsb bsd bse bso bss bst bsx bta btb btd bte bto bts btt btx bxb bxd bxo bxx daa dab dad dae dao das dat dax dba dbb dbd dbe dbo dbs dbt dbx dda ddb ddd dde ddo dds ddt ddx de- dea deb ded dee deo des det dex doa dob dod doe doo dos dot dox dsa dsb dsd dse dso dss dst dsx dta dtb dtd dte dto dts dtt dtx dxd dxo dxs dxt dxx eaa eab ead eae eao eas eat eax eba ebb ebd ebe ebo ebs ebt ebx ed- eda edb edd ede edo eds edt edx eea eeb eed eee eeo ees eet eex eo- eoa eob eod eoe eoo eos eot es- esa esb esd ese eso ess est esx eta etb etd ete eto ets ett etx ex- exa exd exe exo exs ext exx oaa oab oad oae oao oas oat oax ob- oba obb obd obe obo obs obt obx oda odb odd ode odo ods odt oea oeb oed oee oeo oes oet oex oo- ooa oob ood ooo oos oot oox os- osa osb osd ose oso oss ost osx ot- ota otb otd ote oto ots ott ox- oxa oxb oxo oxt oxx saa sab sad sae sao sas sat sax sba sbb sbd sbe sbo sbs sbt sbx sda sdb sdd sde sdo sds sdt se- sea seb sed see seo ses set sex soa sob sod soe soo sos sot sox ss- ssa ssb ssd sse sso sss sst ssx sta stb std ste sto sts stt stx sxs sxt t-x taa tab tad tae tao tas tat tax tba tbb tbd tbe tbo tbs tbt tda tdb tdd tde tdo tds tdt tdx te- tea teb ted tee teo tes tet tex to- toa tob tod toe too tos tot tox tsa tsb tsd tse tso tss tst tsx tta ttb ttd tte tto tts ttt ttx txe txs txt xaa xad xas xat xbe xbx xda xdb xde xds xdt xed xee xes xet xex xoa xod xoo xos xot xox xsa xsb xss xst xts xtx xxo xxx