-er bbb bbe bbi bbr bbs bbt be- beb bee bei ber bes bet bi- bib bie bii bir bis bit brb bre bri brr brs brt bsb bse bsi bsr bss bst btb bte bti btr bts btt ebb ebe ebi ebr ebs ebt eeb eee eer ees eet eib eie eii eir eis eit erb ere eri err ers ert es- esb ese esi esr ess est etb ete eti etr ets ett ibb ibe ibi ibr ibs ibt ie- iee iei ier ies iet iib iie iii iir iis iit ir- irb ire iri irr irs irt is- isb ise isi isr iss ist itb ite iti its itt rbb rbe rbi rbr rbs rbt re- reb ree rei rer res ret rib rie rii rir ris rit rrb rri rrr rrs rrt rsb rse rsi rsr rss rst rtb rte rti rtr rts rtt sbb sbe sbi sbr sbs sbt se- seb see sei ser ses set sib sie sii sir sis sit sr- srb sre sri srr srs srt ss- ssb sse ssi ssr sss sst stb ste sti str sts stt tbb tbe tbi tbr tbs tbt te- teb tee tei ter tes tet tib tie tii tir tis tit trb tre tri trr trs trt tsb tse tsi tsr tss tst ttb tte tti ttr tts ttt