-th a-a a-b a-c a-t aaa aab aac aah aao aat ab- aba abb abc abh abo abt ac- aca acb acc ach aco act aha ahb ahc ahh aho aht aoa aob aoc aoh aoo aot at- ata atb atc ath ato att baa bab bac bah bao bat bba bbb bbc bbh bbo bbt bca bcb bcc bch bco bct bha bhb bhc bhh bho bht boa bob boc boh boo bot bta btb btc bth bto btt c-- caa cab cac cah cao cat cba cbb cbc cbh cbo cbt cca ccb ccc cch cco cct ch- cha chb chc chh cho cht co- coa cob coc coh coo cot cta ctb ctc cth cto ctt haa hab hac hah hao hat hba hbb hbc hbh hbo hbt hca hcb hcc hch hco hct hha hhb hhc hhh hho hht hoa hob hoc hoh hoo hot hta htb htc hth hto htt oaa oab oac oah oao oat ob- oba obb obc obh obo obt oc- oca ocb occ och oco oct oha ohc ohh oho oht oo- ooa oob ooc ooh ooo oot ot- ota otb otc oth oto ott taa tab tac tah tao tat tba tbb tbc tbh tbo tbt tca tcb tcc tch tco tct th- tha thb thc thh tho tht to- toa tob toc toh too tot tta ttb ttc tth tto ttt