-er bbb bbe bbn bbr bbs be- beb bee ben ber bes bnb bne bnn bnr bns brb bre brn brr brs bsb bse bsn bsr bss ebb ebe ebn ebr ebs eeb eee een eer ees en- enb ene enn enr ens erb ere ern err ers es- esb ese esn esr ess nbb nbe nbn nbr nbs ne- neb nee nen ner nes nnb nne nnn nns nrb nre nrn nrr nrs nsb nse nsn nsr nss rbb rbe rbn rbr rbs re- reb ree ren rer res rnb rnn rnr rns rrb rrn rrr rrs rsb rse rsn rsr rss sbb sbe sbn sbr sbs se- seb see sen ser ses snb sne snn snr sns sr- srb sre srn srr srs ss- ssb sse ssn ssr sss