-er bbb bbe bbl bbm bbr bbx be- beb bee bel bem ber bex blb ble bll blm blr blx bmb bme bml bmm bmr bmx brb bre brl brm brr brx bxb bxl bxm bxx ebb ebe ebl ebm ebr ebx eeb eee eel eem eer eex elb ele ell elm elr elx em- emb eme eml emm emr emx erb ere erl erm err ex- exe exl exr exx lbb lbe lbl lbm lbr lbx leb lee lel lem ler lex llb lle lll llm llr lmb lme lml lmm lmr lrb lrm lrr lxr lxx m-r mbb mbe mbl mbm mbr mbx meb mee mel mem mer mex mlb mle mll mlm mlr mlx mmb mme mml mmm mmr mmx mrb mre mrl mrm mrr mrx mxl mxr rbb rbe rbl rbm rbr rbx re- reb ree rel rem rer rex rle rll rlm rlr rmb rme rml rmm rmr rmx rrb rrl rrm rrr rxr xbe xbl xbr xbx xee xel xem xer xex xlb xlm xlr xml xmm xmr xmx xrx xxl xxx