-er bbb bbe bbi bbk bbl bbr bbs be- beb bee bei bek bel ber bes bi- bib bie bii bik bil bir bis bkb bke bkk bkl bkr bks blb ble bli blk bll blr bls brb bre bri brk brl brr brs bsb bse bsi bsk bsl bsr bss ebb ebe ebi ebk ebl ebr ebs eeb eee eek eel eer ees eib eie eii eik eil eir eis ekb eke eki ekl ekr eks elb ele eli elk ell elr els erb ere eri erk erl err ers es- esb ese esi esk esl esr ess ibb ibe ibi ibk ibl ibr ibs ie- iee iei iek iel ier ies iib iie iii iil iir iis ikb ike iki ikk ikl ikr iks il- ilb ile ili ilk ill ilr ils ir- irb ire iri irk irl irr irs is- isb ise isi isk isl isr iss kbb kbe kbi kbk kbl kbr kbs ke- keb kee kei kek kel ker kes kib kie kii kik kil kir kis kkb kke kki kkk kkl kkr kks kl- klb kli klr kls kri krk krl krr krs ksb kse ksi ksk ksl ksr kss lbb lbe lbi lbk lbl lbr lbs leb lee lei lek lel ler les lib lie lii lik lil lir lis lkb lkl lkr lks llb lle lli llk lll llr lls lrb lri lrk lrr lrs lsb lse lsi lsk lsl lsr lss rbb rbe rbi rbk rbl rbr rbs re- reb ree rei rek rel rer res rib rie rii rik ril rir ris rkb rke rkk rks rle rli rll rlr rls rrb rri rrk rrl rrr rrs rsb rse rsi rsk rsl rsr rss sbb sbe sbi sbk sbl sbr sbs se- seb see sei sek sel ser ses sib sie sii sik sil sir sis sk- skb ske ski skk skl skr sks slb sle sli slk sll slr sls sr- srb sre sri srk srl srr srs ss- ssb sse ssi ssk ssl ssr sss