-th a-a a-b a-c a-t aaa aab aac aah aan aat ab- aba abb abc abh abn abt ac- aca acb acc ach acn act aha ahb ahc ahh ahn aht an- ana anb anc anh ann ant at- ata atb atc ath atn att baa bab bac bah ban bat bba bbb bbc bbh bbn bbt bca bcb bcc bch bcn bct bha bhb bhc bhh bht bna bnb bnc bnn bnt bta btb btc bth btn btt c-- caa cab cac cah can cat cba cbb cbc cbh cbn cbt cca ccb ccc cch ccn cct ch- cha chb chc chh chn cht cn- cna cnb cnc cnh cnn cnt cta ctb ctc cth ctn ctt haa hab hac hah han hat hba hbb hbc hbh hbn hbt hca hcb hcc hch hcn hct hha hhb hhc hhh hhn hht hna hnb hnc hnh hnn hnt hta htb htc hth htn htt naa nab nac nah nan nat nba nbb nbc nbn nbt nca ncb ncc nch ncn nct nha nhb nhc nhh nhn nht nna nnb nnc nnh nnn nnt nta ntb ntc nth ntn ntt taa tab tac tah tan tat tba tbb tbc tbh tbn tbt tca tcb tcc tch tcn tct th- tha thb thc thh thn tht tna tnb tnc tnh tnn tnt tta ttb ttc tth ttn ttt