a-a a-b a-t aaa aab aad aak aao aas aat ab- aba abb abd abk abo abs abt ad- ada adb add adk ado ads adt aka akb akd akk ako aks aoa aob aod aok aoo aos aot as- asa asb asd ask aso ass ast at- ata atb atd ato ats att baa bab bad bak bao bas bat bba bbb bbd bbk bbo bbs bbt bda bdb bdd bdk bdo bds bdt bka bkb bkk bko bks bkt boa bob bod bok boo bos bot bsa bsb bsd bsk bso bss bst bta btb btd btk bto bts btt daa dab dad dak dao das dat dba dbb dbd dbk dbo dbs dbt dda ddb ddd ddk ddo dds ddt dka dkb dkk dko dks dkt doa dob dod dok doo dos dot dsa dsb dsd dsk dso dss dst dta dtb dtd dtk dto dts dtt k-t ka- kaa kab kad kak kao kas kat kba kbb kbd kbk kbo kbs kda kdb kdk kdo kds kdt kkb kkk kks kkt koa kob kod kok koo kos kot ksa ksb ksd ksk kso kss kst kta ktb ktk kto kts ktt oaa oab oad oak oao oas oat ob- oba obb obd obk obo obs obt oda odb odd odo ods odt oka okb okd okk oko oks oo- ooa oob ood ook ooo oos oot os- osa osb osd osk oso oss ost ot- ota otb otd otk oto ots ott saa sab sad sak sao sas sat sba sbb sbd sbk sbo sbs sbt sda sdb sdd sdk sdo sds sdt sk- ska skb skd skk sko sks skt soa sob sod sok soo sos sot ss- ssa ssb ssd ssk sso sss sst sta stb std stk sto sts stt taa tab tad tak tao tas tat tba tbb tbd tbk tbo tbs tbt tda tdb tdd tdk tdo tds tdt tka tkb tkk tko tks tkt to- toa tob tod tok too tos tot tsa tsb tsd tsk tso tss tst tta ttb ttd ttk tto tts ttt