-er -ol bbb bbe bbk bbl bbn bbo bbr bbs be- beb bee bek bel ben beo ber bes bkb bke bkk bkl bkn bko bkr bks blb ble blk bll bln blo blr bls bnb bne bnk bnl bnn bno bnr bns bob boe bok bol bon boo bor bos brb bre brk brl brn bro brr brs bsb bse bsk bsl bsn bso bsr bss ebb ebe ebk ebl ebn ebo ebr ebs eeb eee eek eel een eeo eer ees ekb eke ekl eko ekr eks elb ele elk ell eln elo elr els en- enb ene enk enl enn eno enr ens eo- eob eoe eok eol eon eoo eor eos erb ere erk erl ern ero err ers es- esb ese esk esl esn eso esr ess kbb kbe kbk kbl kbn kbo kbr kbs ke- keb kee kek kel ken keo ker kes kkb kke kkk kkl kkn kkr kks kl- klb klo klr kls kn- kne knk knl knn kno knr kob koe kok kol kon koo kor kos krk krl krn kro krr krs ksb kse ksk ksl ksn kso ksr kss lbb lbe lbk lbl lbo lbr lbs leb lee lek lel len leo ler les lkb lkl lkr lks llb lle llk lll lln llo llr lls lnb lne lnk lnl lnn lno lnr lns lob loe lok lol lon loo lor los lrb lrk lrn lro lrr lrs lsb lse lsk lsl lsn lso lsr lss nbb nbe nbk nbl nbn nbo nbr nbs ne- neb nee nek nel nen neo ner nes nke nkk nkn nko nkr nks nlb nle nlk nll nln nlo nlr nls nnb nne nnk nnl nnn nno nns no- nob noe nok nol non noo nor nos nrb nre nrk nrl nrn nro nrr nrs nsb nse nsk nsl nsn nso nsr nss ob- obb obe obk obl obn obo obr obs oeb oee oel oen oeo oer oes okb oke okk okl oko okr oks olb ole olk oll oln olo ols on- onb one onk onl onn ono onr ons oo- oob ook ool oon ooo oor oos or- orb ore ork orl orn oro orr ors os- osb ose osk osl osn oso osr oss rbb rbe rbk rbl rbn rbo rbr rbs re- reb ree rek rel ren reo rer res rkb rke rkk rko rks rle rll rln rlo rlr rls rnb rnn rno rnr rns rob roe rok rol ron roo ror ros rrb rrk rrl rrn rrr rrs rsb rse rsk rsl rsn rso rsr rss sbb sbe sbk sbl sbn sbo sbr sbs se- seb see sek sel sen seo ser ses sk- skb ske skk skl sko skr sks slb sle slk sll sln slo slr sls snb sne snk snl snn sno snr sns sob soe sok sol son soo sor sos sr- srb sre srk srl srn sro srr srs ss- ssb sse ssk ssl ssn sso ssr sss