b-u bbb bbi bbk bbo bbu bi- bib bii bik bio biu bkb bkk bko bob boi bok boo bou bub bui buk buo buu ibb ibi ibk ibo ibu iib iii iio iiu ikb iki ikk iko iku io- iob ioi ioo iou iu- iub iui kbb kbi kbk kbo kbu kib kii kik kio kiu kkb kki kkk kku kob koi kok koo kou kub kui kuk kuu o-i ob- obb obi obk obo obu oib oii oik oio oiu okb oki okk oko oku oo- oob ooi ook ooo ou- oui ouk ouo ubb ubi ubk ubo ubu uib uii uio uiu ukb uki ukk uku uob uok uoo uuu