a-a a-b aaa aab aaf aak aan aau ab- aba abb abf abk abn abu af- afa afb aff afk afn afu aka akb akk akn aku an- ana anb anf ank ann anu au- aua aub auf auk aun b-u baa bab baf bak ban bau bba bbb bbf bbk bbn bbu bfa bfb bff bfn bfu bka bkb bkf bkk bkn bna bnb bnf bnk bnn bnu bua bub buf buk bun buu faa fab faf fak fan fau fba fbb fbf fbk fbn fbu ffa fff ffk ffn ffu fka fkb fkf fkk fna fnb fnf fnk fnn fnu fua fub fuf fuk fun fuu ka- kaa kab kaf kak kan kau kba kbb kbf kbk kbn kbu kfa kff kfu kkb kkk kkn kku kn- kna knf knk knn knu kub kuk kun kuu naa nab naf nak nan nau nba nbb nbf nbk nbn nbu nfa nfb nff nfk nfn nfu nka nkf nkk nkn nku nna nnb nnf nnk nnn nnu nua nub nuk nun nuu ua- uaa uab uaf uak uan uau uba ubb ubf ubk ubn ubu ufa uff ufn ufu uka ukb ukf ukk ukn uku un- una unb unf unk unn unu uua uun uuu