-er b-u bbb bbd bbe bbi bbk bbo bbr bbu bdb bdd bde bdi bdk bdo bdr bdu be- beb bed bee bei bek beo ber beu bi- bib bid bie bii bik bio bir biu bkb bke bkk bko bkr bob bod boe boi bok boo bor bou brb brd bre bri brk bro brr bru bub bud bue bui buk buo bur buu dbb dbd dbe dbi dbk dbo dbr dbu ddb ddd dde ddi ddk ddo ddr ddu de- deb ded dee dei dek deo der deu di- dib did die dii dik dio dir diu dkb dke dki dkk dko dkr dku dob dod doe doi dok doo dor dou drb drd dre dri drk dro drr dru dub dud due dui duk duo dur ebb ebd ebe ebi ebk ebo ebr ebu ed- edb edd ede edi edk edo edr edu eeb eed eee eek eeo eer eib eid eie eii eik eio eir eiu ekb ekd eke eki eko ekr eku eo- eob eod eoe eoi eok eoo eor eou erb erd ere eri erk ero err eru eu- eub eud eue eui eur i-d ibb ibd ibe ibi ibk ibo ibr ibu idb idd ide idi idk ido idr idu ie- ied iee iei iek ier iib iid iie iii iio iir iiu ikb ike iki ikk iko ikr iku io- iob iod ioe ioi ioo ior iou ir- irb ird ire iri irk iro irr iru iu- iub iud iue iui iur kbb kbd kbe kbi kbk kbo kbr kbu kdb kde kdk kdo kdr kdu ke- keb ked kee kei kek keo ker kib kid kie kii kik kio kir kiu kkb kke kki kkk kkr kku kob kod koe koi kok koo kor kou krd kri krk kro krr kru kub kud kue kui kuk kur kuu o-i ob- obb obd obe obi obk obo obr obu odb odd ode odi odo odr odu oeb oed oee oei oeo oer oib oid oie oii oik oio oir oiu okb okd oke oki okk oko okr oku oo- oob ood ooi ook ooo oor or- orb ord ore ori ork oro orr oru ou- oud oue oui ouk ouo our rbb rbd rbe rbi rbk rbo rbr rbu rdb rdd rde rdi rdo rdr rdu re- reb red ree rei rek reo rer reu rib rid rie rii rik rio rir rkb rke rkk rko rku rob rod roe roi rok roo ror rou rrb rrd rri rrk rrr rru rub rud rue rui ruk ruo rur ruu ubb ube ubi ubk ubo ubr ubu udb udd ude udi udk udo udr udu ueb ued uee uei uer uib uid uie uii uio uir uiu ukb uke uki ukk ukr uku uob uod uoe uok uoo uor ur- urb urd ure uri urk uro urr uru uue uur uuu