-er bbb bbe bbi bbk bbl bbr bbs bbt be- beb bee bei bek bel ber bes bet bi- bib bie bii bik bil bir bis bit bkb bke bkk bkl bkr bks bkt blb ble bli blk bll blr bls blt brb bre bri brk brl brr brs brt bsb bse bsi bsk bsl bsr bss bst btb bte bti btk btl btr bts btt ebb ebe ebi ebk ebl ebr ebs ebt eeb eee eek eel eer ees eet eib eie eii eik eil eir eis eit ekb eke eki ekl ekr eks ekt elb ele eli elk ell elr els elt erb ere eri erk erl err ers ert es- esb ese esi esk esl esr ess est etb ete eti etk etl etr ets ett ibb ibe ibi ibk ibl ibr ibs ibt ie- iee iei iek iel ier ies iet iib iie iii iil iir iis iit ikb ike iki ikk ikl ikr iks ikt il- ilb ile ili ilk ill ilr ils ilt ir- irb ire iri irk irl irr irs irt is- isb ise isi isk isl isr iss ist itb ite iti itk itl its itt k-t kbb kbe kbi kbk kbl kbr kbs ke- keb kee kei kek kel ker kes ket kib kie kii kik kil kir kis kit kkb kke kki kkk kkl kkr kks kkt kl- klb kli klr kls klt kri krk krl krr krs krt ksb kse ksi ksk ksl ksr kss kst ktb kte ktk ktl ktr kts ktt lbb lbe lbi lbk lbl lbr lbs lbt leb lee lei lek lel ler les let lib lie lii lik lil lir lis lit lkb lkl lkr lks lkt llb lle lli llk lll llr lls llt lrb lri lrk lrr lrs lrt lsb lse lsi lsk lsl lsr lss lst ltb lte lti ltk ltl ltr lts ltt rbb rbe rbi rbk rbl rbr rbs rbt re- reb ree rei rek rel rer res ret rib rie rii rik ril rir ris rit rkb rke rkk rks rkt rle rli rll rlr rls rlt rrb rri rrk rrl rrr rrs rrt rsb rse rsi rsk rsl rsr rss rst rtb rte rti rtk rtl rtr rts rtt sbb sbe sbi sbk sbl sbr sbs sbt se- seb see sei sek sel ser ses set sib sie sii sik sil sir sis sit sk- skb ske ski skk skl skr sks skt slb sle sli slk sll slr sls slt sr- srb sre sri srk srl srr srs srt ss- ssb sse ssi ssk ssl ssr sss sst stb ste sti stk stl str sts stt tbb tbe tbi tbk tbl tbr tbs tbt te- teb tee tei tek tel ter tes tet tib tie tii tik til tir tis tit tkb tke tkk tkl tkr tks tkt tle tli tlk tll tlr tls tlt trb tre tri trk trl trr trs trt tsb tse tsi tsk tsl tsr tss tst ttb tte tti ttk ttl ttr tts ttt