-th a-a a-b a-c a-t aaa aab aac aad aah aat ab- aba abb abc abd abh abt ac- aca acb acc acd ach act ad- ada adb adc add adh adt aha ahb ahc ahd ahh aht at- ata atb atc atd ath att baa bab bac bad bah bat bba bbb bbc bbd bbh bbt bca bcb bcc bcd bch bct bda bdb bdc bdd bdh bdt bha bhb bhc bhd bhh bht bta btb btc btd bth btt c-- caa cab cac cad cah cat cba cbb cbc cbd cbh cbt cca ccb ccc ccd cch cct cda cdb cdc cdd cdh cdt ch- cha chb chc chd chh cht cta ctb ctc ctd cth ctt daa dab dac dad dah dat dba dbb dbc dbd dbh dbt dca dcb dcc dcd dct dda ddb ddc ddd ddh ddt dh- dha dhb dhc dhd dhh dht dta dtb dtc dtd dth dtt haa hab hac had hah hat hba hbb hbc hbd hbh hbt hca hcb hcc hcd hch hct hda hdb hdc hdd hdh hdt hha hhb hhc hhd hhh hht hta htb htc htd hth htt taa tab tac tad tah tat tba tbb tbc tbd tbh tbt tca tcb tcc tcd tch tct tda tdb tdc tdd tdh tdt th- tha thb thc thd thh tht tta ttb ttc ttd tth ttt