-er a-a a-b aaa aab aad aae aan aar aau aav ab- aba abb abd abe abn abr abu abv ad- ada adb add ade adn adr adu adv aea aeb aed aee aen aer aeu aev an- ana anb and ane ann anr anu anv ar- ara arb ard are arn arr aru arv au- aua aub aud aue aun aur auv av- ava avb avd ave avn avr avu b-u baa bab bad bae ban bar bau bav bba bbb bbd bbe bbn bbr bbu bda bdb bdd bde bdr bdu bdv be- bea beb bed bee ben ber beu bev bna bnb bnd bne bnn bnr bnu bnv bra brb brd bre brn brr bru brv bua bub bud bue bun bur buu bva bvb bvd bve bvn bvr bvu bvv daa dab dad dae dan dar dau dav dba dbb dbd dbe dbn dbr dbu dbv dda ddb ddd dde ddn ddr ddu de- dea deb ded dee den der deu dev dna dnb dnd dne dnn dnr dra drb drd dre drn drr dru drv dua dub dud due dun dur duv dva dvb dvd dve dvn dvr dvu eaa eab ead eae ean ear eau eav eba ebb ebd ebe ebn ebr ebu ebv ed- eda edb edd ede edn edr edu eea eeb eed eee een eer eev en- ena enb end ene enn enr enu env era erb erd ere ern err eru erv eu- eua eub eud eue eun eur euv eva evb evd eve evn evr evv naa nab nad nae nan nar nau nav nba nbb nbd nbe nbn nbr nbu nbv nda ndb ndd nde ndn ndr ndu ndv ne- nea neb ned nee nen ner neu nev nna nnb nne nnn nnu nnv nra nrb nrd nre nrn nrr nru nrv nua nub nud nue nun nur nuu nuv nva nvb nvd nve nvn nvu nvv ra- raa rab rad rae ran rar rau rav rba rbb rbd rbe rbn rbr rbu rda rdb rdd rde rdn rdr rdu rdv re- rea reb red ree ren rer reu rev rna rnb rnd rnn rnr rnu rnv rra rrb rrd rrn rrr rru rua rub rud rue run rur ruu ruv rva rvb rvd rve rvn rvr rvu rvv ua- uaa uab uad uae uan uar uau uav uba ubb ube ubn ubr ubu ubv uda udb udd ude udn udr udu udv uea ueb ued uee uen uer un- una unb und une unn unr unu unv ur- ura urb urd ure urn urr uru uua uue uun uur uuu uva uvb uve uvu uvv v-a v-e vaa vab vad vae van var vau vav vba vbd vbr vbv vdb vdd vde vdr vdu vdv vea veb ved vee ven ver veu vn- vna vnd vnr vnu vnv vra vrb vrd vre vrn vrr vru vue vur vuv vva vvb vvr vvv