-er bbb bbe bbm bbr bbs bbt be- beb bee bem ber bes bet bmb bme bmm bmr bms bmt brb bre brm brr brs brt bsb bse bsm bsr bss bst btb bte btm btr bts btt ebb ebe ebm ebr ebs ebt eeb eee eem eer ees eet em- emb eme emm emr ems emt erb ere erm err ers ert es- esb ese esm esr ess est etb ete etm etr ets ett m-r mbb mbe mbm mbr mbs mbt meb mee mem mer mes met mmb mme mmm mmr mms mmt mrb mre mrm mrr mrs mrt msb mse msm msr mss mst mtb mte mtm mtr mts mtt rbb rbe rbm rbr rbs rbt re- reb ree rem rer res ret rmb rme rmm rmr rms rmt rrb rrm rrr rrs rrt rsb rse rsm rsr rss rst rtb rte rtm rtr rts rtt sbb sbe sbm sbr sbs sbt se- seb see sem ser ses set smb sme smm smr sms smt sr- srb sre srm srr srs srt ss- ssb sse ssm ssr sss sst stb ste stm str sts stt tbb tbe tbm tbr tbs tbt te- teb tee tem ter tes tet tmb tme tmm tmr tms tmt trb tre trm trr trs trt tsb tse tsm tsr tss tst ttb tte ttm ttr tts ttt