-er -ol bbb bbe bbi bbk bbl bbo bbr bbs be- beb bee bei bek bel beo ber bes bi- bib bie bii bik bil bio bir bis bkb bke bkk bkl bko bkr bks blb ble bli blk bll blo blr bls bob boe boi bok bol boo bor bos brb bre bri brk brl bro brr brs bsb bse bsi bsk bsl bso bsr bss ebb ebe ebi ebk ebl ebo ebr ebs eeb eee eek eel eeo eer ees eib eie eii eik eil eio eir eis ekb eke eki ekl eko ekr eks elb ele eli elk ell elo elr els eo- eob eoe eoi eok eol eoo eor eos erb ere eri erk erl ero err ers es- esb ese esi esk esl eso esr ess ibb ibe ibi ibk ibl ibo ibr ibs ie- iee iei iek iel ier ies iib iie iii iil iio iir iis ikb ike iki ikk ikl iko ikr iks il- ilb ile ili ilk ill ilo ilr ils io- iob ioe ioi iol ioo ior ios ir- irb ire iri irk irl iro irr irs is- isb ise isi isk isl iso isr iss kbb kbe kbi kbk kbl kbo kbr kbs ke- keb kee kei kek kel keo ker kes kib kie kii kik kil kio kir kis kkb kke kki kkk kkl kkr kks kl- klb kli klo klr kls kob koe koi kok kol koo kor kos kri krk krl kro krr krs ksb kse ksi ksk ksl kso ksr kss lbb lbe lbi lbk lbl lbo lbr lbs leb lee lei lek lel leo ler les lib lie lii lik lil lio lir lis lkb lkl lkr lks llb lle lli llk lll llo llr lls lob loe loi lok lol loo lor los lrb lri lrk lro lrr lrs lsb lse lsi lsk lsl lso lsr lss o-i ob- obb obe obi obk obl obo obr obs oeb oee oei oel oeo oer oes oib oie oii oik oil oio oir ois okb oke oki okk okl oko okr oks olb ole oli olk oll olo ols oo- oob ooi ook ool ooo oor oos or- orb ore ori ork orl oro orr ors os- osb ose osi osk osl oso osr oss rbb rbe rbi rbk rbl rbo rbr rbs re- reb ree rei rek rel reo rer res rib rie rii rik ril rio rir ris rkb rke rkk rko rks rle rli rll rlo rlr rls rob roe roi rok rol roo ror ros rrb rri rrk rrl rrr rrs rsb rse rsi rsk rsl rso rsr rss sbb sbe sbi sbk sbl sbo sbr sbs se- seb see sei sek sel seo ser ses sib sie sii sik sil sio sir sis sk- skb ske ski skk skl sko skr sks slb sle sli slk sll slo slr sls sob soe soi sok sol soo sor sos sr- srb sre sri srk srl sro srr srs ss- ssb sse ssi ssk ssl sso ssr sss