a-a a-b aaa aab aad aan aar aav ab- aba abb abd abn abr abv ad- ada adb add adn adr adv an- ana anb and ann anr anv ar- ara arb ard arn arr arv av- ava avb avd avn avr baa bab bad ban bar bav bba bbb bbd bbn bbr bda bdb bdd bdr bdv bna bnb bnd bnn bnr bnv bra brb brd brn brr brv bva bvb bvd bvn bvr bvv daa dab dad dan dar dav dba dbb dbd dbn dbr dbv dda ddb ddd ddn ddr dna dnb dnd dnn dnr dra drb drd drn drr drv dva dvb dvd dvn dvr naa nab nad nan nar nav nba nbb nbd nbn nbr nbv nda ndb ndd ndn ndr ndv nna nnb nnn nnv nra nrb nrd nrn nrr nrv nva nvb nvd nvn nvv ra- raa rab rad ran rar rav rba rbb rbd rbn rbr rda rdb rdd rdn rdr rdv rna rnb rnd rnn rnr rnv rra rrb rrd rrn rrr rva rvb rvd rvn rvr rvv v-a vaa vab vad van var vav vba vbd vbr vbv vdb vdd vdr vdv vn- vna vnd vnr vnv vra vrb vrd vrn vrr vva vvb vvr vvv