-er b-u bbb bbe bbg bbk bbn bbo bbr bbu be- beb bee beg bek ben beo ber beu bgb bge bgg bgk bgn bgo bgr bgu bkb bke bkg bkk bkn bko bkr bnb bne bng bnk bnn bno bnr bnu bob boe bog bok bon boo bor bou brb bre brg brk brn bro brr bru bub bue bug buk bun buo bur buu ebb ebe ebg ebk ebn ebo ebr ebu eeb eee eeg eek een eeo eer egb ege egg egn ego egr egu ekb eke ekg eko ekr eku en- enb ene eng enk enn eno enr enu eo- eob eoe eog eok eon eoo eor eou erb ere erg erk ern ero err eru eu- eub eue eug eun eur gbe gbg gbk gbn gbo gbr gbu ge- geb gee geg gek gen geo ger geu ggb ggg ggn ggo ggr ggu gkb gkn gko gnb gne gnn gno gnr gnu gob goe gog gok gon goo gor gou grb gre grg grk grn gro grr gru gu- gub gue gug guk gun guo gur guu kbb kbe kbk kbn kbo kbr kbu ke- keb kee keg kek ken keo ker kgb kgo kgu kkb kke kkk kkn kkr kku kn- kne kng knk knn kno knr knu kob koe kog kok kon koo kor kou krg krk krn kro krr kru kub kue kug kuk kun kur kuu nbb nbe nbg nbk nbn nbo nbr nbu ne- neb nee neg nek nen neo ner neu ngb nge ngg ngk ngn ngo ngu nke nkk nkn nko nkr nku nnb nne nng nnk nnn nno nnu no- nob noe nog nok non noo nor nou nrb nre nrg nrk nrn nro nrr nru nub nue nug nuk nun nuo nur nuu ob- obb obe obg obk obn obo obr obu oeb oee oeg oen oeo oer oge ogg ogn ogo okb oke okg okk oko okr oku on- onb one ong onk onn ono onr onu oo- oob oog ook oon ooo oor or- orb ore org ork orn oro orr oru ou- oue ouk oun ouo our rbb rbe rbg rbk rbn rbo rbr rbu re- reb ree reg rek ren reo rer reu rgb rge rgg rgk rgn rgo rgr rkb rke rkg rkk rko rku rnb rng rnn rno rnr rnu rob roe rog rok ron roo ror rou rrb rrg rrk rrn rrr rru rub rue rug ruk run ruo rur ruu ubb ube ubg ubk ubn ubo ubr ubu ueb uee ueg uen uer ugb uge ugg ugk ugn ugo ugr ugu ukb uke ukk ukn ukr uku un- unb une ung unk unn uno unr unu uob uoe uog uok uon uoo uor ur- urb ure urg urk urn uro urr uru uue uug uun uur uuu