a-a a-b a-t aaa aab aad aao aas aat ab- aba abb abd abo abs abt ad- ada adb add ado ads adt aoa aob aod aoo aos aot as- asa asb asd aso ass ast at- ata atb atd ato ats att baa bab bad bao bas bat bba bbb bbd bbo bbs bbt bda bdb bdd bdo bds bdt boa bob bod boo bos bot bsa bsb bsd bso bss bst bta btb btd bto bts btt daa dab dad dao das dat dba dbb dbd dbo dbs dbt dda ddb ddd ddo dds ddt doa dob dod doo dos dot dsa dsb dsd dso dss dst dta dtb dtd dto dts dtt oaa oab oad oao oas oat ob- oba obb obd obo obs obt oda odb odd odo ods odt oo- ooa oob ood ooo oos oot os- osa osb osd oso oss ost ot- ota otb otd oto ots ott saa sab sad sao sas sat sba sbb sbd sbo sbs sbt sda sdb sdd sdo sds sdt soa sob sod soo sos sot ss- ssa ssb ssd sso sss sst sta stb std sto sts stt taa tab tad tao tas tat tba tbb tbd tbo tbs tbt tda tdb tdd tdo tds tdt to- toa tob tod too tos tot tsa tsb tsd tso tss tst tta ttb ttd tto tts ttt