-er bbb bbe bbf bbi bbl bbr bbx be- beb bee bef bei bel ber bex bfb bfe bff bfi bfl bfr bfx bi- bib bie bif bii bil bir bix blb ble blf bli bll blr blx brb bre brf bri brl brr brx bxb bxi bxl bxx ebb ebe ebf ebi ebl ebr ebx eeb eee eef eel eer eex ef- efb efe eff efi efl efr efx eib eie eif eii eil eir eix elb ele elf eli ell elr elx erb ere erf eri erl err ex- exe exi exl exr exx fbb fbe fbf fbi fbl fbr fbx feb fee fef fei fel fer fex ffe fff ffi ffl ffr ffx fib fie fif fii fil fir fix flb fle flf fli fll flr flx frb fre frf fri frl frr fxe fxi fxr fxx i-f ibb ibe ibf ibi ibl ibr ibx ie- iee ief iei iel ier iex ifb ife iff ifi ifl ifr ifx iib iie iif iii iil iir iix il- ilb ile ilf ili ill ilr ilx ir- irb ire irf iri irl irr irx ixe ixi ixl lbb lbe lbf lbi lbl lbr lbx leb lee lef lei lel ler lex lfb lfe lff lfi lfl lfr lfx lib lie lif lii lil lir lix llb lle llf lli lll llr lrb lrf lri lrr lxi lxr lxx rbb rbe rbf rbi rbl rbr rbx re- reb ree ref rei rel rer rex rfb rfe rff rfi rfl rfr rib rie rif rii ril rir rix rle rlf rli rll rlr rrb rrf rri rrl rrr rxr xbe xbl xbr xbx xee xel xer xex xfe xfl xfx xie xii xix xlb xlf xli xlr xrf xrx xxi xxl xxx