b-u bbb bbk bbn bbo bbu bkb bkk bkn bko bnb bnk bnn bno bnu bob bok bon boo bou bub buk bun buo buu kbb kbk kbn kbo kbu kkb kkk kkn kku kn- knk knn kno knu kob kok kon koo kou kub kuk kun kuu nbb nbk nbn nbo nbu nkk nkn nko nku nnb nnk nnn nno nnu no- nob nok non noo nou nub nuk nun nuo nuu ob- obb obk obn obo obu okb okk oko oku on- onb onk onn ono onu oo- oob ook oon ooo ou- ouk oun ouo ubb ubk ubn ubo ubu ukb ukk ukn uku un- unb unk unn uno unu uob uok uon uoo uun uuu