a-a a-b aaa aab aad aau aay ab- aba abb abd abu aby ad- ada adb add adu ady au- aua aub aud ay- aya ayd ayu b-u baa bab bad bau bay bba bbb bbd bbu bby bda bdb bdd bdu bdy bua bub bud buu buy by- bya byd byu daa dab dad dau day dba dbb dbd dbu dby dda ddb ddd ddu ddy dua dub dud duy dy- dya dyb dyd dyu dyy ua- uaa uab uad uau uay uba ubb ubu uby uda udb udd udu uua uuu uyu yaa yab yad yau yay yby yda ydy yua yud yuu yuy yyb yyu yyy