-er b-u bbb bbe bbi bbm bbr bbu bbx be- beb bee bei bem ber beu bex bi- bib bie bii bim bir biu bix bmb bme bmi bmm bmr bmu bmx brb bre bri brm brr bru brx bub bue bui bum bur buu bux bxb bxi bxm bxx ebb ebe ebi ebm ebr ebu ebx eeb eee eem eer eex eib eie eii eim eir eiu eix em- emb eme emi emm emr emu emx erb ere eri erm err eru eu- eub eue eui eur eux ex- exe exi exr exu exx ibb ibe ibi ibm ibr ibu ibx ie- iee iei iem ier iex iib iie iii iim iir iiu iix im- imb ime imi imm imu imx ir- irb ire iri irm irr iru irx iu- iub iue iui ium iur ixe ixi m-r mbb mbe mbi mbm mbr mbu mbx meb mee mei mem mer meu mex mi- mib mie mii mim mir miu mix mmb mme mmi mmm mmr mmu mmx mrb mre mri mrm mrr mru mrx mub mue mui mum mur muu mux mxi mxr mxu rbb rbe rbi rbm rbr rbu rbx re- reb ree rei rem rer reu rex rib rie rii rim rir rix rmb rme rmi rmm rmr rmx rrb rri rrm rrr rru rub rue rui rum rur ruu rux rxr ubb ube ubi ubr ubu ubx ueb uee uei uem uer uib uie uii uim uir uiu um- umb ume umi umm umr umu ur- urb ure uri urm urr uru urx uue uum uur uuu uxb uxr uxu xbe xbr xbx xee xem xer xeu xex xie xii xiu xix xmi xmm xmr xmu xmx xrx xue xui xxi xxx