bbb bbe bbi bbm bbx be- beb bee bei bem bex bi- bib bie bii bim bix bmb bme bmi bmm bmx bxb bxi bxm bxx ebb ebe ebi ebm ebx eeb eee eem eex eib eie eii eim eix em- emb eme emi emm emx ex- exe exi exx ibb ibe ibi ibm ibx ie- iee iei iem iex iib iie iii iim iix im- imb ime imi imm imx ixe ixi mbb mbe mbi mbm mbx meb mee mei mem mex mi- mib mie mii mim mix mmb mme mmi mmm mmx mxi xbe xbx xee xem xex xie xii xix xmi xmm xmx xxi xxx