-er -up b-p b-u bbb bbe bbk bbn bbo bbp bbr bbu be- beb bee bek ben beo bep ber beu bkb bke bkk bkn bko bkp bkr bnb bne bnk bnn bno bnp bnr bnu bob boe bok bon boo bop bor bou bpb bpe bpn bpo bpp bpr bpu brb bre brk brn bro brp brr bru bub bue buk bun buo bup bur buu ebb ebe ebk ebn ebo ebp ebr ebu eeb eee eek een eeo eep eer ekb eke eko ekp ekr eku en- enb ene enk enn eno enp enr enu eo- eob eoe eok eon eoo eop eor eou ep- epb epe epn epo epp epr epu erb ere erk ern ero erp err eru eu- eub eue eun eup eur kbb kbe kbk kbn kbo kbp kbr kbu ke- keb kee kek ken keo kep ker kkb kke kkk kkn kkp kkr kku kn- kne knk knn kno knp knr knu kob koe kok kon koo kop kor kou kpe kpk kpn kpo kpp kpr kpu krk krn kro krp krr kru kub kue kuk kun kup kur kuu nbb nbe nbk nbn nbo nbp nbr nbu ne- neb nee nek nen neo nep ner neu nke nkk nkn nko nkp nkr nku nnb nne nnk nnn nno nnp nnu no- nob noe nok non noo nop nor nou npb npe npn npo npp npr npu nrb nre nrk nrn nro nrp nrr nru nub nue nuk nun nuo nup nur nuu ob- obb obe obk obn obo obp obr obu oeb oee oen oeo oep oer okb oke okk oko okp okr oku on- onb one onk onn ono onp onr onu oo- oob ook oon ooo oop oor op- opb ope opk opn opo opp opr or- orb ore ork orn oro orp orr oru ou- oue ouk oun ouo oup our p-p pbb pbe pbk pbn pbo pbp pbr pbu peb pee pek pen peo pep per peu pkb pke pkn pko pkp pkr pku pn- pnb pne pnk pnn pno pnp pnr pnu pob poe pok pon poo pop por pou ppb ppe ppk ppn ppo ppp ppr ppu prb pre prk prn pro prp prr pru pub pue puk pun pup pur puu rbb rbe rbk rbn rbo rbp rbr rbu re- reb ree rek ren reo rep rer reu rkb rke rkk rko rkp rku rnb rnn rno rnp rnr rnu rob roe rok ron roo rop ror rou rpb rpe rpk rpn rpo rpp rpr rpu rrb rrk rrn rrp rrr rru rub rue ruk run ruo rup rur ruu ubb ube ubk ubn ubo ubp ubr ubu ueb uee uen uep uer ukb uke ukk ukn ukp ukr uku un- unb une unk unn uno unp unr unu uob uoe uok uon uoo uop uor up- upb upe upk upn upo upp upr upu ur- urb ure urk urn uro urp urr uru uue uun uur uuu