bbb bbe bbf bbi bbl bbx be- beb bee bef bei bel bex bfb bfe bff bfi bfl bfx bi- bib bie bif bii bil bix blb ble blf bli bll blx bxb bxi bxl bxx ebb ebe ebf ebi ebl ebx eeb eee eef eel eex ef- efb efe eff efi efl efx eib eie eif eii eil eix elb ele elf eli ell elx ex- exe exi exl exx fbb fbe fbf fbi fbl fbx feb fee fef fei fel fex ffe fff ffi ffl ffx fib fie fif fii fil fix flb fle flf fli fll flx fxe fxi fxx i-f ibb ibe ibf ibi ibl ibx ie- iee ief iei iel iex ifb ife iff ifi ifl ifx iib iie iif iii iil iix il- ilb ile ilf ili ill ilx ixe ixi ixl lbb lbe lbf lbi lbl lbx leb lee lef lei lel lex lfb lfe lff lfi lfl lfx lib lie lif lii lil lix llb lle llf lli lll lxi lxx xbe xbl xbx xee xel xex xfe xfl xfx xie xii xix xlb xlf xli xxi xxl xxx