a-a a-b aaa aab aah aao aay ab- aba abb abh abo aby aha ahb ahh aho ahy aoa aob aoh aoo ay- aya ayh ayo baa bab bah bao bay bba bbb bbh bbo bby bha bhb bhh bho boa bob boh boo boy by- bya byh byo haa hab hah hao hay hba hbb hbh hbo hby hha hhb hhh hho hhy hoa hob hoh hoo hoy hy- hya hyb hyh hyo hyy oaa oab oah oao ob- oba obb obh obo oby oha ohh oho oo- ooa oob ooh ooo oya oyo yaa yab yah yao yay yby yha yob yoo yoy yyb yyy