-er bbb bbe bbn bbr bbs be- beb bee ben ber bes bev bnb bne bnn bnr bns bnv brb bre brn brr brs brv bsb bse bsn bsr bss bsv bvb bve bvn bvr bvs bvv ebb ebe ebn ebr ebs ebv eeb eee een eer ees eev en- enb ene enn enr ens env erb ere ern err ers erv es- esb ese esn esr ess esv evb eve evn evr evs evv nbb nbe nbn nbr nbs nbv ne- neb nee nen ner nes nev nnb nne nnn nns nnv nrb nre nrn nrr nrs nrv nsb nse nsn nsr nss nsv nvb nve nvn nvv rbb rbe rbn rbr rbs re- reb ree ren rer res rev rnb rnn rnr rns rnv rrb rrn rrr rrs rsb rse rsn rsr rss rsv rvb rve rvn rvr rvs rvv sbb sbe sbn sbr sbs sbv se- seb see sen ser ses sev snb sne snn snr sns snv sr- srb sre srn srr srs srv ss- ssb sse ssn ssr sss ssv svb sve svn svr svs svv v-e vbr vbs vbv veb vee ven ver ves vn- vnr vns vnv vrb vre vrn vrr vrs vsb vse vsn vsr vss vsv vvb vvr vvs vvv