a-a a-b a-i a-t aaa aab aag aai aat aay ab- aba abb abg abi abt aby ag- aga agb agg agi agt agy ai- aia aib aig aii ait aiy at- ata atb atg ati att ay- aya ayi ayt baa bab bag bai bat bay bba bbb bbg bbi bbt bby bga bgb bgg bgi bgt bi- bia bib big bii bit biy bta btb btg bti btt bty by- bya byg byi byt gaa gab gag gai gat gay gba gbg gbi gbt gby gga ggb ggg ggi ggt gia gib gig gii git giy gta gtb gtg gti gtt gty gy- gya gyb ia- iaa iab iag iai iat iba ibb ibg ibi ibt iby iga igb igg igi igt igy iia iib iii iit ita itb itg iti itt ity iya iyt iyy taa tab tag tai tat tay tba tbb tbg tbi tbt tga tgb tgg tgi tgt tgy tia tib tig tii tit tiy tta ttb ttg tti ttt tty tya tyg tyt yaa yab yag yai yat yay ybg ybi yby yga yig yii yit yta ytt yyb yyg yyt yyy