b-u bbb bbk bbm bbn bbo bbr bbu bkb bkk bkm bkn bko bkr bmb bmk bmm bmn bmo bmr bmu bnb bnk bnn bno bnr bnu bob bok bom bon boo bor bou brb brk brm brn bro brr bru bub buk bum bun buo bur buu kbb kbk kbm kbn kbo kbr kbu kkb kkk kkm kkn kkr kku kmb kmk kmm kmo kmu kn- knk knm knn kno knr knu kob kok kom kon koo kor kou krk krn kro krr kru kub kuk kum kun kur kuu m-o m-r mbb mbk mbm mbo mbr mbu mkb mkk mkm mkn mko mkr mku mmb mmk mmm mmn mmo mmr mmu mnb mnk mnm mnn mno mnr mnu mob mok mom mon moo mor mou mrb mrk mrm mrn mro mrr mru mub muk mum mun mur muu nbb nbk nbm nbn nbo nbr nbu nkk nkm nkn nko nkr nku nmb nmk nmm nmn nmo nmr nmu nnb nnk nnm nnn nno nnu no- nob nok nom non noo nor nou nrb nrk nrm nrn nro nrr nru nub nuk num nun nuo nur nuu ob- obb obk obm obn obo obr obu okb okk oko okr oku om- omb omm omn omo omr omu on- onb onk onn ono onr onu oo- oob ook oom oon ooo oor or- orb ork orm orn oro orr oru ou- ouk oum oun ouo our rbb rbk rbm rbn rbo rbr rbu rkb rkk rkm rko rku rmb rmm rmn rmo rmr rnb rnm rnn rno rnr rnu rob rok rom ron roo ror rou rrb rrk rrm rrn rrr rru rub ruk rum run ruo rur ruu ubb ubk ubn ubo ubr ubu ukb ukk ukn ukr uku um- umb umm umn umo umr umu un- unb unk unm unn uno unr unu uob uok uom uon uoo uor ur- urb urk urm urn uro urr uru uum uun uur uuu