-er b-p bbb bbe bbm bbp bbr be- beb bee bem bep ber bmb bme bmm bmp bmr bpb bpe bpm bpp bpr brb bre brm brp brr ebb ebe ebm ebp ebr eeb eee eem eep eer em- emb eme emm emp emr ep- epb epe epm epp epr erb ere erm erp err m-r mbb mbe mbm mbp mbr meb mee mem mep mer mmb mme mmm mmp mmr mpb mpe mpm mpp mpr mrb mre mrm mrp mrr p-p pbb pbe pbm pbp pbr peb pee pem pep per pmb pme pmm pmp pmr ppb ppe ppm ppp ppr prb pre prm prp prr rbb rbe rbm rbp rbr re- reb ree rem rep rer rmb rme rmm rmp rmr rpb rpe rpm rpp rpr rrb rrm rrp rrr