-th a-a a-b a-t aaa aab aad aah aat aay ab- aba abb abd abh abt aby ad- ada adb add adh adt ady aha ahb ahd ahh aht ahy at- ata atb atd ath att ay- aya ayd ayh ayt baa bab bad bah bat bay bba bbb bbd bbh bbt bby bda bdb bdd bdh bdt bdy bha bhb bhd bhh bht bta btb btd bth btt bty by- bya byd byh byt daa dab dad dah dat day dba dbb dbd dbh dbt dby dda ddb ddd ddh ddt ddy dh- dha dhb dhd dhh dht dta dtb dtd dth dtt dty dy- dya dyb dyd dyy haa hab had hah hat hay hba hbb hbd hbh hbt hby hda hdb hdd hdh hdt hdy hha hhb hhd hhh hht hhy hta htb htd hth htt hty hy- hya hyb hyd hyh hyt hyy taa tab tad tah tat tay tba tbb tbd tbh tbt tda tdb tdd tdh tdt tdy th- tha thb thd thh tht thy tta ttb ttd tth ttt tty tya tyd tyt yaa yab yad yah yat yay yby yda ydt ydy yha yht yta ytd yth ytt yyb yyt yyy