-th a-a a-b a-c a-t aaa aab aac aah aas aat ab- aba abb abc abh abs abt ac- aca acb acc ach acs act aha ahb ahc ahh ahs aht as- asa asb asc ash ass ast at- ata atb atc ath ats att baa bab bac bah bas bat bba bbb bbc bbh bbs bbt bca bcb bcc bch bcs bct bha bhb bhc bhh bhs bht bsa bsb bsc bsh bss bst bta btb btc bth bts btt c-- caa cab cac cah cas cat cba cbb cbc cbh cbs cbt cca ccb ccc cch ccs cct ch- cha chb chc chh chs cht csa csb csc csh css cst cta ctb ctc cth cts ctt haa hab hac hah has hat hba hbb hbc hbh hbs hbt hca hcb hcc hch hcs hct hha hhb hhc hhh hhs hht hsa hsb hsc hsh hss hst hta htb htc hth hts htt saa sab sac sah sas sat sba sbb sbc sbh sbs sbt sca scb scc sch scs sct sh- sha shb shc shh shs sht ss- ssa ssb ssc ssh sss sst sta stb stc sth sts stt taa tab tac tah tas tat tba tbb tbc tbh tbs tbt tca tcb tcc tch tcs tct th- tha thb thc thh ths tht tsa tsb tsc tsh tss tst tta ttb ttc tth tts ttt