a-a a-b aaa aab aam aao aav ab- aba abb abm abo abv ama amb amm amo amv aoa aob aom aoo aov av- ava avb avm avo baa bab bam bao bav bba bbb bbm bbo bma bmb bmm bmo bmv boa bob bom boo bov bva bvb bvm bvo bvv m-o m-v maa mab mam mao mav mba mbb mbm mbo mbv mma mmb mmm mmo mmv moa mob mom moo mov mva mvb mvm mvo mvv oaa oab oam oao oav ob- oba obb obm obo obv om- oma omb omm omo omv oo- ooa oob oom ooo oov ov- ova ovb ovo ovv v-a vaa vab vam vao vav vba vbm vbo vbv vm- vma vmm vmo voa vob vom voo vov vva vvb vvm vvo vvv