a-a a-b a-i a-t aaa aab aag aai aao aat ab- aba abb abg abi abo abt ag- aga agb agg agi ago agt ai- aia aib aig aii aio ait aoa aob aog aoi aoo aot at- ata atb atg ati ato att baa bab bag bai bao bat bba bbb bbg bbi bbo bbt bga bgb bgg bgi bgo bgt bi- bia bib big bii bio bit boa bob bog boi boo bot bta btb btg bti bto btt gaa gab gag gai gao gat gba gbg gbi gbo gbt gga ggb ggg ggi ggo ggt gia gib gig gii gio git goa gob gog goi goo got gta gtb gtg gti gto gtt ia- iaa iab iag iai iao iat iba ibb ibg ibi ibo ibt iga igb igg igi igo igt iia iib iii iio iit io- ioa iob iog ioi ioo iot ita itb itg iti ito itt o-i oaa oab oag oai oao oat ob- oba obb obg obi obo obt oga ogg ogi ogo ogt oia oib oii oio oit oo- ooa oob oog ooi ooo oot ot- ota otb otg oti oto ott taa tab tag tai tao tat tba tbb tbg tbi tbo tbt tga tgb tgg tgi tgo tgt tia tib tig tii tio tit to- toa tob tog toi too tot tta ttb ttg tti tto ttt