a-a a-b a-i aaa aab aag aai aak ab- aba abb abg abi abk ag- aga agb agg agi agk ai- aia aib aig aii aik aka akb akg aki akk baa bab bag bai bak bba bbb bbg bbi bbk bga bgb bgg bgi bgk bi- bia bib big bii bik bka bkb bkg bkk gaa gab gag gai gak gba gbg gbi gbk gga ggb ggg ggi gia gib gig gii gik gka gkb ia- iaa iab iag iai iba ibb ibg ibi ibk iga igb igg igi igk iia iib iii ika ikb iki ikk ka- kaa kab kag kai kak kba kbb kbi kbk kga kgb kgi kia kib kig kii kik kkb kki kkk