a-a a-b aaa aab aad aan aao aav ab- aba abb abd abn abo abv ad- ada adb add adn ado adv an- ana anb and ann ano anv aoa aob aod aon aoo aov av- ava avb avd avn avo baa bab bad ban bao bav bba bbb bbd bbn bbo bda bdb bdd bdo bdv bna bnb bnd bnn bno bnv boa bob bod bon boo bov bva bvb bvd bvn bvo bvv daa dab dad dan dao dav dba dbb dbd dbn dbo dbv dda ddb ddd ddn ddo dna dnb dnd dnn dno doa dob dod don doo dov dva dvb dvd dvn naa nab nad nan nao nav nba nbb nbd nbn nbo nbv nda ndb ndd ndn ndo ndv nna nnb nnn nno nnv no- noa nob nod non noo nov nva nvb nvd nvn nvv oaa oab oad oan oao oav ob- oba obb obd obn obo obv oda odb odd odn odo odv on- ona onb ond onn ono oo- ooa oob ood oon ooo oov ov- ova ovb ovd ovo ovv v-a vaa vab vad van vao vav vba vbd vbo vbv vdb vdd vdo vdv vn- vna vnd vno vnv voa vob vod von voo vov vva vvb vvo vvv