a-a a-b aaa aab aad aaf aan aao aar aav ab- aba abb abd abf abn abo abr abv ad- ada adb add adf adn ado adr adv af- afa afb afd aff afn afo afr afv an- ana anb and anf ann ano anr anv aoa aob aod aof aon aoo aor aov ar- ara arb ard arf arn aro arr arv av- ava avb avd avf avn avo avr baa bab bad baf ban bao bar bav bba bbb bbd bbf bbn bbo bbr bda bdb bdd bdf bdo bdr bdv bfa bfb bfd bff bfn bfo bfr bfv bna bnb bnd bnf bnn bno bnr bnv boa bob bod bof bon boo bor bov bra brb brd brf brn bro brr brv bva bvb bvd bvn bvo bvr bvv daa dab dad daf dan dao dar dav dba dbb dbd dbf dbn dbo dbr dbv dda ddb ddd ddf ddn ddo ddr dfa dfb dfd dff dfn dfo dfr dfv dna dnb dnd dnf dnn dno dnr doa dob dod dof don doo dor dov dra drb drd drn dro drr drv dva dvb dvd dvn dvr faa fab fad faf fan fao far fav fba fbb fbd fbf fbn fbo fbr fda fdb fdd fdf fdn fdo fdr ffa ffd fff ffn ffo ffr ffv fna fnb fnd fnf fnn fnr fnv foa fob fof fon foo for fra frb frd frf frn fro frr fva fvd naa nab nad naf nan nao nar nav nba nbb nbd nbf nbn nbo nbr nbv nda ndb ndd ndf ndn ndo ndr ndv nfa nfb nfd nff nfn nfo nfr nfv nna nnb nnf nnn nno nnv no- noa nob nod nof non noo nor nov nra nrb nrd nrf nrn nro nrr nrv nva nvb nvd nvn nvv oaa oab oad oaf oan oao oar oav ob- oba obb obd obf obn obo obr obv oda odb odd odf odn odo odr odv of- ofa ofb ofd off ofn ofo ofr ofv on- ona onb ond onf onn ono onr oo- ooa oob ood oof oon ooo oor oov or- ora orb ord orf orn oro orr orv ov- ova ovb ovd ovf ovo ovv ra- raa rab rad raf ran rao rar rav rba rbb rbd rbf rbn rbo rbr rda rdb rdd rdf rdn rdo rdr rdv rfa rfb rfd rff rfn rfo rfr rfv rna rnb rnd rnn rno rnr rnv roa rob rod rof ron roo ror rov rra rrb rrd rrf rrn rrr rva rvb rvd rvf rvn rvo rvr rvv v-a vaa vab vad van vao var vav vba vbd vbo vbr vbv vdb vdd vdf vdo vdr vdv vfa vfb vfd vff vfn vfr vfv vn- vna vnd vnf vno vnr vnv voa vob vod vof von voo vor vov vra vrb vrd vrf vrn vrr vva vvb vvo vvr vvv