-er bbb bbe bbf bbi bbo bbr bbx be- beb bee bef bei beo ber bex bfb bfe bff bfi bfo bfr bfx bi- bib bie bif bii bio bir bix bob boe bof boi boo bor box brb bre brf bri bro brr brx bxb bxi bxo bxx ebb ebe ebf ebi ebo ebr ebx eeb eee eef eeo eer eex ef- efb efe eff efi efo efr efx eib eie eif eii eio eir eix eo- eob eoe eof eoi eoo eor erb ere erf eri ero err ex- exe exi exo exr exx fbb fbe fbf fbi fbo fbr fbx feb fee fef fei feo fer fex ffe fff ffi ffo ffr ffx fib fie fif fii fir fix fob foe fof foi foo for fox frb fre frf fri fro frr fxe fxi fxr fxx i-f ibb ibe ibf ibi ibo ibr ibx ie- iee ief iei ier iex ifb ife iff ifi ifo ifr ifx iib iie iif iii iio iir iix io- iob ioe iof ioi ioo ior ir- irb ire irf iri iro irr irx ixe ixi o-i ob- obb obe obf obi obo obr obx oeb oee oef oei oeo oer oex of- ofb ofe off ofi ofo ofr ofx oib oie oif oii oio oir oo- oob oof ooi ooo oor oox or- orb ore orf ori oro orr orx ox- oxb oxf oxi oxo oxx rbb rbe rbf rbi rbo rbr rbx re- reb ree ref rei reo rer rex rfb rfe rff rfi rfo rfr rib rie rif rii rio rir rix rob roe rof roi roo ror rox rrb rrf rri rrr rxr xbe xbr xbx xee xer xex xfe xfx xie xii xio xix xof xoi xoo xor xox xrf xrx xxi xxo xxx