a-a a-b aaa aab aag aah aak ab- aba abb abg abh abk ag- aga agb agg agh agk aha ahb ahg ahh ahk aka akb akg akh akk baa bab bag bah bak bba bbb bbg bbh bbk bga bgb bgg bgh bgk bha bhb bhg bhh bhk bka bkb bkg bkk gaa gab gag gah gak gba gbg gbh gbk gga ggb ggg ggh gha ghb ghg ghh gka gkb gkh haa hab hag hah hak hba hbb hbg hbh hbk hga hgb hgg hgh hgk hha hhb hhg hhh hhk hka hkb hkg hkh hkk ka- kaa kab kag kah kak kba kbb kbh kbk kga kgb kgh kha khh khk kkb kkh kkk