-er b-u bbb bbd bbe bbk bbn bbo bbr bbu bdb bdd bde bdk bdo bdr bdu be- beb bed bee bek ben beo ber beu bkb bke bkk bkn bko bkr bnb bnd bne bnk bnn bno bnr bnu bob bod boe bok bon boo bor bou brb brd bre brk brn bro brr bru bub bud bue buk bun buo bur buu dbb dbd dbe dbk dbn dbo dbr dbu ddb ddd dde ddk ddn ddo ddr ddu de- deb ded dee dek den deo der deu dkb dke dkk dko dkr dku dnb dnd dne dnk dnn dno dnr dob dod doe dok don doo dor dou drb drd dre drk drn dro drr dru dub dud due duk dun duo dur ebb ebd ebe ebk ebn ebo ebr ebu ed- edb edd ede edk edn edo edr edu eeb eed eee eek een eeo eer ekb ekd eke eko ekr eku en- enb end ene enk enn eno enr enu eo- eob eod eoe eok eon eoo eor eou erb erd ere erk ern ero err eru eu- eub eud eue eun eur kbb kbd kbe kbk kbn kbo kbr kbu kdb kde kdk kdo kdr kdu ke- keb ked kee kek ken keo ker kkb kke kkk kkn kkr kku kn- knd kne knk knn kno knr knu kob kod koe kok kon koo kor kou krd krk krn kro krr kru kub kud kue kuk kun kur kuu nbb nbd nbe nbk nbn nbo nbr nbu ndb ndd nde ndk ndn ndo ndr ndu ne- neb ned nee nek nen neo ner neu nke nkk nkn nko nkr nku nnb nne nnk nnn nno nnu no- nob nod noe nok non noo nor nou nrb nrd nre nrk nrn nro nrr nru nub nud nue nuk nun nuo nur nuu ob- obb obd obe obk obn obo obr obu odb odd ode odn odo odr odu oeb oed oee oen oeo oer okb okd oke okk oko okr oku on- onb ond one onk onn ono onr onu oo- oob ood ook oon ooo oor or- orb ord ore ork orn oro orr oru ou- oud oue ouk oun ouo our rbb rbd rbe rbk rbn rbo rbr rbu rdb rdd rde rdn rdo rdr rdu re- reb red ree rek ren reo rer reu rkb rke rkk rko rku rnb rnd rnn rno rnr rnu rob rod roe rok ron roo ror rou rrb rrd rrk rrn rrr rru rub rud rue ruk run ruo rur ruu ubb ube ubk ubn ubo ubr ubu udb udd ude udk udn udo udr udu ueb ued uee uen uer ukb uke ukk ukn ukr uku un- unb und une unk unn uno unr unu uob uod uoe uok uon uoo uor ur- urb urd ure urk urn uro urr uru uue uun uur uuu