a-a a-b aaa aab aak aan aao aau ab- aba abb abk abn abo abu aka akb akk akn ako aku an- ana anb ank ann ano anu aoa aob aok aon aoo aou au- aua aub auk aun auo b-u baa bab bak ban bao bau bba bbb bbk bbn bbo bbu bka bkb bkk bkn bko bna bnb bnk bnn bno bnu boa bob bok bon boo bou bua bub buk bun buo buu ka- kaa kab kak kan kao kau kba kbb kbk kbn kbo kbu kkb kkk kkn kku kn- kna knk knn kno knu koa kob kok kon koo kou kub kuk kun kuu naa nab nak nan nao nau nba nbb nbk nbn nbo nbu nka nkk nkn nko nku nna nnb nnk nnn nno nnu no- noa nob nok non noo nou nua nub nuk nun nuo nuu oaa oab oak oan oao oau ob- oba obb obk obn obo obu oka okb okk oko oku on- ona onb onk onn ono onu oo- ooa oob ook oon ooo ou- oua ouk oun ouo ua- uaa uab uak uan uao uau uba ubb ubk ubn ubo ubu uka ukb ukk ukn uku un- una unb unk unn uno unu uoa uob uok uon uoo uua uun uuu