-er b-p bbb bbe bbm bbp bbr bbs be- beb bee bem bep ber bes bmb bme bmm bmp bmr bms bpb bpe bpm bpp bpr bps brb bre brm brp brr brs bsb bse bsm bsp bsr bss ebb ebe ebm ebp ebr ebs eeb eee eem eep eer ees em- emb eme emm emp emr ems ep- epb epe epm epp epr eps erb ere erm erp err ers es- esb ese esm esp esr ess m-r mbb mbe mbm mbp mbr mbs meb mee mem mep mer mes mmb mme mmm mmp mmr mms mpb mpe mpm mpp mpr mps mrb mre mrm mrp mrr mrs msb mse msm msp msr mss p-p pbb pbe pbm pbp pbr pbs peb pee pem pep per pes pmb pme pmm pmp pmr pms ppb ppe ppm ppp ppr pps prb pre prm prp prr prs ps- psb pse psm psp psr pss rbb rbe rbm rbp rbr rbs re- reb ree rem rep rer res rmb rme rmm rmp rmr rms rpb rpe rpm rpp rpr rps rrb rrm rrp rrr rrs rsb rse rsm rsp rsr rss sbb sbe sbm sbp sbr sbs se- seb see sem sep ser ses smb sme smm smp smr sms spb spe spm spp spr sps sr- srb sre srm srp srr srs ss- ssb sse ssm ssp ssr sss