-th a-a a-b a-t aaa aab aah aan aat ab- aba abb abh abn abt aha ahb ahh ahn aht an- ana anb anh ann ant at- ata atb ath atn att baa bab bah ban bat bba bbb bbh bbn bbt bha bhb bhh bht bna bnb bnn bnt bta btb bth btn btt haa hab hah han hat hba hbb hbh hbn hbt hha hhb hhh hhn hht hna hnb hnh hnn hnt hta htb hth htn htt naa nab nah nan nat nba nbb nbn nbt nha nhb nhh nhn nht nna nnb nnh nnn nnt nta ntb nth ntn ntt taa tab tah tan tat tba tbb tbh tbn tbt th- tha thb thh thn tht tna tnb tnh tnn tnt tta ttb tth ttn ttt