-er a-a a-b aaa aab aad aae aan aar aau ab- aba abb abd abe abn abr abu ad- ada adb add ade adn adr adu aea aeb aed aee aen aer aeu an- ana anb and ane ann anr anu ar- ara arb ard are arn arr aru au- aua aub aud aue aun aur b-u baa bab bad bae ban bar bau bba bbb bbd bbe bbn bbr bbu bda bdb bdd bde bdr bdu be- bea beb bed bee ben ber beu bna bnb bnd bne bnn bnr bnu bra brb brd bre brn brr bru bua bub bud bue bun bur buu daa dab dad dae dan dar dau dba dbb dbd dbe dbn dbr dbu dda ddb ddd dde ddn ddr ddu de- dea deb ded dee den der deu dna dnb dnd dne dnn dnr dra drb drd dre drn drr dru dua dub dud due dun dur eaa eab ead eae ean ear eau eba ebb ebd ebe ebn ebr ebu ed- eda edb edd ede edn edr edu eea eeb eed eee een eer en- ena enb end ene enn enr enu era erb erd ere ern err eru eu- eua eub eud eue eun eur naa nab nad nae nan nar nau nba nbb nbd nbe nbn nbr nbu nda ndb ndd nde ndn ndr ndu ne- nea neb ned nee nen ner neu nna nnb nne nnn nnu nra nrb nrd nre nrn nrr nru nua nub nud nue nun nur nuu ra- raa rab rad rae ran rar rau rba rbb rbd rbe rbn rbr rbu rda rdb rdd rde rdn rdr rdu re- rea reb red ree ren rer reu rna rnb rnd rnn rnr rnu rra rrb rrd rrn rrr rru rua rub rud rue run rur ruu ua- uaa uab uad uae uan uar uau uba ubb ube ubn ubr ubu uda udb udd ude udn udr udu uea ueb ued uee uen uer un- una unb und une unn unr unu ur- ura urb urd ure urn urr uru uua uue uun uur uuu