-er a-a a-b aaa aab aad aae aak aan aar aau ab- aba abb abd abe abk abn abr abu ad- ada adb add ade adk adn adr adu aea aeb aed aee aek aen aer aeu aka akb akd ake akk akn akr aku an- ana anb and ane ank ann anr anu ar- ara arb ard are ark arn arr aru au- aua aub aud aue auk aun aur b-u baa bab bad bae bak ban bar bau bba bbb bbd bbe bbk bbn bbr bbu bda bdb bdd bde bdk bdr bdu be- bea beb bed bee bek ben ber beu bka bkb bke bkk bkn bkr bna bnb bnd bne bnk bnn bnr bnu bra brb brd bre brk brn brr bru bua bub bud bue buk bun bur buu daa dab dad dae dak dan dar dau dba dbb dbd dbe dbk dbn dbr dbu dda ddb ddd dde ddk ddn ddr ddu de- dea deb ded dee dek den der deu dka dkb dke dkk dkr dku dna dnb dnd dne dnk dnn dnr dra drb drd dre drk drn drr dru dua dub dud due duk dun dur eaa eab ead eae eak ean ear eau eba ebb ebd ebe ebk ebn ebr ebu ed- eda edb edd ede edk edn edr edu eea eeb eed eee eek een eer eka ekb ekd eke ekr eku en- ena enb end ene enk enn enr enu era erb erd ere erk ern err eru eu- eua eub eud eue eun eur ka- kaa kab kad kae kak kan kar kau kba kbb kbd kbe kbk kbn kbr kbu kda kdb kde kdk kdr kdu ke- kea keb ked kee kek ken ker kkb kke kkk kkn kkr kku kn- kna knd kne knk knn knr knu kra krd krk krn krr kru kub kud kue kuk kun kur kuu naa nab nad nae nak nan nar nau nba nbb nbd nbe nbk nbn nbr nbu nda ndb ndd nde ndk ndn ndr ndu ne- nea neb ned nee nek nen ner neu nka nke nkk nkn nkr nku nna nnb nne nnk nnn nnu nra nrb nrd nre nrk nrn nrr nru nua nub nud nue nuk nun nur nuu ra- raa rab rad rae rak ran rar rau rba rbb rbd rbe rbk rbn rbr rbu rda rdb rdd rde rdn rdr rdu re- rea reb red ree rek ren rer reu rkb rke rkk rku rna rnb rnd rnn rnr rnu rra rrb rrd rrk rrn rrr rru rua rub rud rue ruk run rur ruu ua- uaa uab uad uae uak uan uar uau uba ubb ube ubk ubn ubr ubu uda udb udd ude udk udn udr udu uea ueb ued uee uen uer uka ukb uke ukk ukn ukr uku un- una unb und une unk unn unr unu ur- ura urb urd ure urk urn urr uru uua uue uun uur uuu