a-a a-b a-t aaa aab aag aat aay ab- aba abb abg abt aby ag- aga agb agg agt agy at- ata atb atg att ay- aya ayt baa bab bag bat bay bba bbb bbg bbt bby bga bgb bgg bgt bta btb btg btt bty by- bya byg byt gaa gab gag gat gay gba gbg gbt gby gga ggb ggg ggt gta gtb gtg gtt gty gy- gya gyb taa tab tag tat tay tba tbb tbg tbt tga tgb tgg tgt tgy tta ttb ttg ttt tty tya tyg tyt yaa yab yag yat yay ybg yby yga yta ytt yyb yyg yyt yyy