a-a a-b aaa aab aam aao aar aav ab- aba abb abm abo abr abv ama amb amm amo amr amv aoa aob aom aoo aor aov ar- ara arb arm aro arr arv av- ava avb avm avo avr baa bab bam bao bar bav bba bbb bbm bbo bbr bma bmb bmm bmo bmr bmv boa bob bom boo bor bov bra brb brm bro brr brv bva bvb bvm bvo bvr bvv m-o m-r m-v maa mab mam mao mar mav mba mbb mbm mbo mbr mbv mma mmb mmm mmo mmr mmv moa mob mom moo mor mov mra mrb mrm mro mrr mrv mva mvb mvm mvo mvr mvv oaa oab oam oao oar oav ob- oba obb obm obo obr obv om- oma omb omm omo omr omv oo- ooa oob oom ooo oor oov or- ora orb orm oro orr orv ov- ova ovb ovo ovv ra- raa rab ram rao rar rav rba rbb rbm rbo rbr rma rmb rmm rmo rmr rmv roa rob rom roo ror rov rra rrb rrm rrr rva rvb rvm rvo rvr rvv v-a vaa vab vam vao var vav vba vbm vbo vbr vbv vm- vma vmm vmo vmr voa vob vom voo vor vov vra vrb vrm vrr vva vvb vvm vvo vvr vvv