a-a a-b a-i aaa aab aag aai aay ab- aba abb abg abi aby ag- aga agb agg agi agy ai- aia aib aig aii aiy ay- aya ayi baa bab bag bai bay bba bbb bbg bbi bby bga bgb bgg bgi bi- bia bib big bii biy by- bya byg byi gaa gab gag gai gay gba gbg gbi gby gga ggb ggg ggi gia gib gig gii giy gy- gya gyb ia- iaa iab iag iai iba ibb ibg ibi iby iga igb igg igi igy iia iib iii iya iyy yaa yab yag yai yay ybg ybi yby yga yig yii yyb yyg yyy