a-a a-b aaa aab aan aao aau aav ab- aba abb abn abo abu abv an- ana anb ann ano anu anv aoa aob aon aoo aou aov au- aua aub aun auo auv av- ava avb avn avo avu b-u baa bab ban bao bau bav bba bbb bbn bbo bbu bna bnb bnn bno bnu bnv boa bob bon boo bou bov bua bub bun buo buu bva bvb bvn bvo bvu bvv naa nab nan nao nau nav nba nbb nbn nbo nbu nbv nna nnb nnn nno nnu nnv no- noa nob non noo nou nov nua nub nun nuo nuu nuv nva nvb nvn nvu nvv oaa oab oan oao oau oav ob- oba obb obn obo obu obv on- ona onb onn ono onu oo- ooa oob oon ooo oov ou- oua oun ouo ov- ova ovb ovo ovv ua- uaa uab uan uao uau uav uba ubb ubn ubo ubu ubv un- una unb unn uno unu unv uoa uob uon uoo uua uun uuu uva uvb uvo uvu uvv v-a vaa vab van vao vau vav vba vbo vbv vn- vna vno vnu vnv voa vob von voo vou vov vuv vva vvb vvo vvv