-er bbb bbe bbi bbn bbr bbx be- beb bee bei ben ber bex bi- bib bie bii bin bir bix bnb bne bni bnn bnr bnx brb bre bri brn brr brx bxb bxi bxn bxx ebb ebe ebi ebn ebr ebx eeb eee een eer eex eib eie eii ein eir eix en- enb ene eni enn enr erb ere eri ern err ex- exe exi exr exx ibb ibe ibi ibn ibr ibx ie- iee iei ien ier iex iib iie iii iin iir iix in- inb ine ini inn inr inx ir- irb ire iri irn irr irx ixe ixi ixn n-i nbb nbe nbi nbn nbr nbx ne- neb nee nei nen ner nex nib nie nii nin nir nix nnb nne nni nnn nrb nre nri nrn nrr nrx rbb rbe rbi rbn rbr rbx re- reb ree rei ren rer rex rib rie rii rin rir rix rnb rni rnn rnr rrb rri rrn rrr rxr xbe xbr xbx xee xen xer xex xie xii xin xix xrx xxi xxx