a-a a-b a-i aaa aab aai aak aao aay ab- aba abb abi abk abo aby ai- aia aib aii aik aio aiy aka akb aki akk ako aoa aob aoi aok aoo ay- aya ayi ayk ayo baa bab bai bak bao bay bba bbb bbi bbk bbo bby bi- bia bib bii bik bio biy bka bkb bkk bko boa bob boi bok boo boy by- bya byi byk byo ia- iaa iab iai iao iba ibb ibi ibk ibo iby iia iib iii iio ika ikb iki ikk iko io- ioa iob ioi ioo iya iyo iyy ka- kaa kab kai kak kao kay kba kbb kbi kbk kbo kia kib kii kik kio kkb kki kkk kky koa kob koi kok koo koy kya kyo o-i oaa oab oai oak oao ob- oba obb obi obk obo oby oia oib oii oik oio oka okb oki okk oko oo- ooa oob ooi ook ooo oya oyi oyo yaa yab yai yak yao yay ybi yby yii yio yka yki ykk yob yoi yok yoo yoy yyb yyy