-th a-a a-b a-c a-t aaa aab aac aae aah aan aat ab- aba abb abc abe abh abn abt ac- aca acb acc ace ach acn act aea aeb aec aee aeh aen aet aha ahb ahc ahe ahh ahn aht an- ana anb anc ane anh ann ant at- ata atb atc ate ath atn att baa bab bac bae bah ban bat bba bbb bbc bbe bbh bbn bbt bca bcb bcc bce bch bcn bct be- bea beb bec bee beh ben bet bha bhb bhc bhe bhh bht bna bnb bnc bne bnn bnt bta btb btc bte bth btn btt c-- caa cab cac cae cah can cat cba cbb cbc cbe cbh cbn cbt cca ccb ccc cce cch ccn cct ce- cea ceb cec cee ceh cen cet ch- cha chb chc che chh chn cht cn- cna cnb cnc cne cnh cnn cnt cta ctb ctc cte cth ctn ctt eaa eab eac eae eah ean eat eba ebb ebc ebe ebh ebn ebt ec- eca ecb ecc ece ech ecn ect eea eeb eec eee een eet eha ehb ehc ehe ehh ehn eht en- ena enb enc ene enh enn ent eta etb etc ete eth etn ett haa hab hac hae hah han hat hba hbb hbc hbe hbh hbn hbt hca hcb hcc hce hch hcn hct he- hea heb hec hee heh hen het hha hhb hhc hhe hhh hhn hht hna hnb hnc hne hnh hnn hnt hta htb htc hte hth htn htt naa nab nac nae nah nan nat nba nbb nbc nbe nbn nbt nca ncb ncc nce nch ncn nct ne- nea neb nec nee neh nen net nha nhb nhc nhe nhh nhn nht nna nnb nnc nne nnh nnn nnt nta ntb ntc nte nth ntn ntt taa tab tac tae tah tan tat tba tbb tbc tbe tbh tbn tbt tca tcb tcc tce tch tcn tct te- tea teb tec tee teh ten tet th- tha thb thc the thh thn tht tna tnb tnc tne tnh tnn tnt tta ttb ttc tte tth ttn ttt