-th a-a a-b a-t aaa aab aah aao aas aat ab- aba abb abh abo abs abt aha ahb ahh aho ahs aht aoa aob aoh aoo aos aot as- asa asb ash aso ass ast at- ata atb ath ato ats att baa bab bah bao bas bat bba bbb bbh bbo bbs bbt bha bhb bhh bho bhs bht boa bob boh boo bos bot bsa bsb bsh bso bss bst bta btb bth bto bts btt haa hab hah hao has hat hba hbb hbh hbo hbs hbt hha hhb hhh hho hhs hht hoa hob hoh hoo hos hot hsa hsb hsh hss hst hta htb hth hto hts htt oaa oab oah oao oas oat ob- oba obb obh obo obs obt oha ohh oho ohs oht oo- ooa oob ooh ooo oos oot os- osa osb osh oso oss ost ot- ota otb oth oto ots ott saa sab sah sao sas sat sba sbb sbh sbo sbs sbt sh- sha shb shh sho shs sht soa sob soh soo sos sot ss- ssa ssb ssh sso sss sst sta stb sth sto sts stt taa tab tah tao tas tat tba tbb tbh tbo tbs tbt th- tha thb thh tho ths tht to- toa tob toh too tos tot tsa tsb tsh tso tss tst tta ttb tth tto tts ttt