-er bbb bbe bbi bbm bbr bbx be- beb bee bei bem ber bex bi- bib bie bii bim bir bix bmb bme bmi bmm bmr bmx brb bre bri brm brr brx bxb bxi bxm bxx ebb ebe ebi ebm ebr ebx eeb eee eem eer eex eib eie eii eim eir eix em- emb eme emi emm emr emx erb ere eri erm err ex- exe exi exr exx ibb ibe ibi ibm ibr ibx ie- iee iei iem ier iex iib iie iii iim iir iix im- imb ime imi imm imx ir- irb ire iri irm irr irx ixe ixi m-r mbb mbe mbi mbm mbr mbx meb mee mei mem mer mex mi- mib mie mii mim mir mix mmb mme mmi mmm mmr mmx mrb mre mri mrm mrr mrx mxi mxr rbb rbe rbi rbm rbr rbx re- reb ree rei rem rer rex rib rie rii rim rir rix rmb rme rmi rmm rmr rmx rrb rri rrm rrr rxr xbe xbr xbx xee xem xer xex xie xii xix xmi xmm xmr xmx xrx xxi xxx