a-a a-b aaa aab aag aah aao aay ab- aba abb abg abh abo aby ag- aga agb agg agh ago agy aha ahb ahg ahh aho ahy aoa aob aog aoh aoo ay- aya ayh ayo baa bab bag bah bao bay bba bbb bbg bbh bbo bby bga bgb bgg bgh bgo bha bhb bhg bhh bho boa bob bog boh boo boy by- bya byg byh byo gaa gab gag gah gao gay gba gbg gbh gbo gby gga ggb ggg ggh ggo gha ghb ghg ghh gho goa gob gog goh goo goy gy- gya gyb gyo haa hab hag hah hao hay hba hbb hbg hbh hbo hby hga hgb hgg hgh hgo hgy hha hhb hhg hhh hho hhy hoa hob hog hoh hoo hoy hy- hya hyb hyg hyh hyo hyy oaa oab oag oah oao ob- oba obb obg obh obo oby oga ogg ogh ogo ogy oha ohg ohh oho oo- ooa oob oog ooh ooo oya oyo yaa yab yag yah yao yay ybg yby yga ygo yha yob yog yoo yoy yyb yyg yyy