bbb bbe bbi bbl bbx be- beb bee bei bel bex bi- bib bie bii bil bix blb ble bli bll blx bxb bxi bxl bxx ebb ebe ebi ebl ebx eeb eee eel eex eib eie eii eil eix elb ele eli ell elx ex- exe exi exl exx ibb ibe ibi ibl ibx ie- iee iei iel iex iib iie iii iil iix il- ilb ile ili ill ilx ixe ixi ixl lbb lbe lbi lbl lbx leb lee lei lel lex lib lie lii lil lix llb lle lli lll lxi lxx xbe xbl xbx xee xel xex xie xii xix xlb xli xxi xxl xxx