a-a a-b a-t aaa aab aad aae aak aao aas aat ab- aba abb abd abe abk abo abs abt ad- ada adb add ade adk ado ads adt aea aeb aed aee aek aeo aes aet aka akb akd ake akk ako aks aoa aob aod aoe aok aoo aos aot as- asa asb asd ase ask aso ass ast at- ata atb atd ate ato ats att baa bab bad bae bak bao bas bat bba bbb bbd bbe bbk bbo bbs bbt bda bdb bdd bde bdk bdo bds bdt be- bea beb bed bee bek beo bes bet bka bkb bke bkk bko bks bkt boa bob bod boe bok boo bos bot bsa bsb bsd bse bsk bso bss bst bta btb btd bte btk bto bts btt daa dab dad dae dak dao das dat dba dbb dbd dbe dbk dbo dbs dbt dda ddb ddd dde ddk ddo dds ddt de- dea deb ded dee dek deo des det dka dkb dke dkk dko dks dkt doa dob dod doe dok doo dos dot dsa dsb dsd dse dsk dso dss dst dta dtb dtd dte dtk dto dts dtt eaa eab ead eae eak eao eas eat eba ebb ebd ebe ebk ebo ebs ebt ed- eda edb edd ede edk edo eds edt eea eeb eed eee eek eeo ees eet eka ekb ekd eke eko eks ekt eo- eoa eob eod eoe eok eoo eos eot es- esa esb esd ese esk eso ess est eta etb etd ete etk eto ets ett k-t ka- kaa kab kad kae kak kao kas kat kba kbb kbd kbe kbk kbo kbs kda kdb kde kdk kdo kds kdt ke- kea keb ked kee kek keo kes ket kkb kke kkk kks kkt koa kob kod koe kok koo kos kot ksa ksb ksd kse ksk kso kss kst kta ktb kte ktk kto kts ktt oaa oab oad oae oak oao oas oat ob- oba obb obd obe obk obo obs obt oda odb odd ode odo ods odt oea oeb oed oee oeo oes oet oka okb okd oke okk oko oks oo- ooa oob ood ook ooo oos oot os- osa osb osd ose osk oso oss ost ot- ota otb otd ote otk oto ots ott saa sab sad sae sak sao sas sat sba sbb sbd sbe sbk sbo sbs sbt sda sdb sdd sde sdk sdo sds sdt se- sea seb sed see sek seo ses set sk- ska skb skd ske skk sko sks skt soa sob sod soe sok soo sos sot ss- ssa ssb ssd sse ssk sso sss sst sta stb std ste stk sto sts stt taa tab tad tae tak tao tas tat tba tbb tbd tbe tbk tbo tbs tbt tda tdb tdd tde tdk tdo tds tdt te- tea teb ted tee tek teo tes tet tka tkb tke tkk tko tks tkt to- toa tob tod toe tok too tos tot tsa tsb tsd tse tsk tso tss tst tta ttb ttd tte ttk tto tts ttt