-er bbb bbe bbf bbi bbk bbl bbr bbs be- beb bee bef bei bek bel ber bes bfb bfe bff bfi bfl bfr bfs bi- bib bie bif bii bik bil bir bis bkb bke bkf bkk bkl bkr bks blb ble blf bli blk bll blr bls brb bre brf bri brk brl brr brs bsb bse bsf bsi bsk bsl bsr bss ebb ebe ebf ebi ebk ebl ebr ebs eeb eee eef eek eel eer ees ef- efb efe eff efi efl efr efs eib eie eif eii eik eil eir eis ekb eke ekf eki ekl ekr eks elb ele elf eli elk ell elr els erb ere erf eri erk erl err ers es- esb ese esf esi esk esl esr ess fbb fbe fbf fbi fbk fbl fbr fbs feb fee fef fei fek fel fer fes ffe fff ffi ffk ffl ffr ffs fib fie fif fii fik fil fir fis fkb fkf fki fkk fkl flb fle flf fli fll flr fls frb fre frf fri frk frl frr frs fsb fse fsf fsi fsk fsl fsr fss i-f ibb ibe ibf ibi ibk ibl ibr ibs ie- iee ief iei iek iel ier ies ifb ife iff ifi ifl ifr ifs iib iie iif iii iil iir iis ikb ike ikf iki ikk ikl ikr iks il- ilb ile ilf ili ilk ill ilr ils ir- irb ire irf iri irk irl irr irs is- isb ise isf isi isk isl isr iss kbb kbe kbf kbi kbk kbl kbr kbs ke- keb kee kef kei kek kel ker kes kff kfi kfs kib kie kif kii kik kil kir kis kkb kke kki kkk kkl kkr kks kl- klb klf kli klr kls krf kri krk krl krr krs ksb kse ksf ksi ksk ksl ksr kss lbb lbe lbf lbi lbk lbl lbr lbs leb lee lef lei lek lel ler les lfb lfe lff lfi lfk lfl lfr lfs lib lie lif lii lik lil lir lis lkb lkl lkr lks llb lle llf lli llk lll llr lls lrb lrf lri lrk lrr lrs lsb lse lsf lsi lsk lsl lsr lss rbb rbe rbf rbi rbk rbl rbr rbs re- reb ree ref rei rek rel rer res rfb rfe rff rfi rfk rfl rfr rfs rib rie rif rii rik ril rir ris rkb rke rkf rkk rks rle rlf rli rll rlr rls rrb rrf rri rrk rrl rrr rrs rsb rse rsf rsi rsk rsl rsr rss sbb sbe sbf sbi sbk sbl sbr sbs se- seb see sef sei sek sel ser ses sfb sfe sff sfi sfk sfl sfr sfs sib sie sif sii sik sil sir sis sk- skb ske skf ski skk skl skr sks slb sle slf sli slk sll slr sls sr- srb sre srf sri srk srl srr srs ss- ssb sse ssf ssi ssk ssl ssr sss