a-a a-b a-t aaa aab aad aae aan aas aat ab- aba abb abd abe abn abs abt ad- ada adb add ade adn ads adt aea aeb aed aee aen aes aet an- ana anb and ane ann ans ant as- asa asb asd ase asn ass ast at- ata atb atd ate atn ats att baa bab bad bae ban bas bat bba bbb bbd bbe bbn bbs bbt bda bdb bdd bde bds bdt be- bea beb bed bee ben bes bet bna bnb bnd bne bnn bns bnt bsa bsb bsd bse bsn bss bst bta btb btd bte btn bts btt daa dab dad dae dan das dat dba dbb dbd dbe dbn dbs dbt dda ddb ddd dde ddn dds ddt de- dea deb ded dee den des det dna dnb dnd dne dnn dns dnt dsa dsb dsd dse dsn dss dst dta dtb dtd dte dtn dts dtt eaa eab ead eae ean eas eat eba ebb ebd ebe ebn ebs ebt ed- eda edb edd ede edn eds edt eea eeb eed eee een ees eet en- ena enb end ene enn ens ent es- esa esb esd ese esn ess est eta etb etd ete etn ets ett naa nab nad nae nan nas nat nba nbb nbd nbe nbn nbs nbt nda ndb ndd nde ndn nds ndt ne- nea neb ned nee nen nes net nna nnb nne nnn nns nnt nsa nsb nsd nse nsn nss nst nta ntb ntd nte ntn nts ntt saa sab sad sae san sas sat sba sbb sbd sbe sbn sbs sbt sda sdb sdd sde sdn sds sdt se- sea seb sed see sen ses set sna snb snd sne snn sns snt ss- ssa ssb ssd sse ssn sss sst sta stb std ste stn sts stt taa tab tad tae tan tas tat tba tbb tbd tbe tbn tbs tbt tda tdb tdd tde tdn tds tdt te- tea teb ted tee ten tes tet tna tnb tnd tne tnn tns tnt tsa tsb tsd tse tsn tss tst tta ttb ttd tte ttn tts ttt