a-a a-b a-i a-t aaa aab aag aai aak aao aat ab- aba abb abg abi abk abo abt ag- aga agb agg agi agk ago agt ai- aia aib aig aii aik aio ait aka akb akg aki akk ako aoa aob aog aoi aok aoo aot at- ata atb atg ati ato att baa bab bag bai bak bao bat bba bbb bbg bbi bbk bbo bbt bga bgb bgg bgi bgk bgo bgt bi- bia bib big bii bik bio bit bka bkb bkg bkk bko bkt boa bob bog boi bok boo bot bta btb btg bti btk bto btt gaa gab gag gai gak gao gat gba gbg gbi gbk gbo gbt gga ggb ggg ggi ggo ggt gia gib gig gii gik gio git gka gkb gko gkt goa gob gog goi gok goo got gta gtb gtg gti gtk gto gtt ia- iaa iab iag iai iao iat iba ibb ibg ibi ibk ibo ibt iga igb igg igi igk igo igt iia iib iii iio iit ika ikb iki ikk iko ikt io- ioa iob iog ioi ioo iot ita itb itg iti itk ito itt k-t ka- kaa kab kag kai kak kao kat kba kbb kbi kbk kbo kga kgb kgi kgo kia kib kig kii kik kio kit kkb kki kkk kkt koa kob kog koi kok koo kot kta ktb ktg ktk kto ktt o-i oaa oab oag oai oak oao oat ob- oba obb obg obi obk obo obt oga ogg ogi ogo ogt oia oib oii oik oio oit oka okb okg oki okk oko oo- ooa oob oog ooi ook ooo oot ot- ota otb otg oti otk oto ott taa tab tag tai tak tao tat tba tbb tbg tbi tbk tbo tbt tga tgb tgg tgi tgk tgo tgt tia tib tig tii tik tio tit tka tkb tkg tkk tko tkt to- toa tob tog toi tok too tot tta ttb ttg tti ttk tto ttt