b-u bbb bbi bbn bbr bbu bi- bib bii bin bir biu biz bnb bni bnn bnr bnu bnz brb bri brn brr bru brz bub bui bun bur buu buz bzn bzr bzu bzz ibb ibi ibn ibr ibu ibz iib iii iin iir iiu in- inb ini inn inr inu ir- irb iri irn irr iru iu- iub iui iur iuz izi izu izz n-i nbb nbi nbn nbr nbu nib nii nin nir niu niz nnb nni nnn nnu nnz nrb nri nrn nrr nru nrz nub nui nun nur nuu nzb nzi nzz rbb rbi rbn rbr rbu rib rii rin rir riz rnb rni rnn rnr rnu rnz rrb rri rrn rrr rru rub rui run rur ruu ruz rzb ubb ubi ubn ubr ubu uib uii uin uir uiu un- unb uni unn unr unu ur- urb uri urn urr uru urz uun uur uuu uzb uzi uzu zbb zbr zib zin zir ziz znn zub zui zun zur zuz zzr zzz