b-u bbb bbi bbn bbo bbr bbu bi- bib bii bin bio bir biu bnb bni bnn bno bnr bnu bob boi bon boo bor bou brb bri brn bro brr bru bub bui bun buo bur buu ibb ibi ibn ibo ibr ibu iib iii iin iio iir iiu in- inb ini inn ino inr inu io- iob ioi ion ioo ior iou ir- irb iri irn iro irr iru iu- iub iui iur n-i nbb nbi nbn nbo nbr nbu nib nii nin nio nir niu nnb nni nnn nno nnu no- nob noi non noo nor nou nrb nri nrn nro nrr nru nub nui nun nuo nur nuu o-i ob- obb obi obn obo obr obu oib oii oin oio oir oiu on- onb oni onn ono onr onu oo- oob ooi oon ooo oor or- orb ori orn oro orr oru ou- oui oun ouo our rbb rbi rbn rbo rbr rbu rib rii rin rio rir rnb rni rnn rno rnr rnu rob roi ron roo ror rou rrb rri rrn rrr rru rub rui run ruo rur ruu ubb ubi ubn ubo ubr ubu uib uii uin uio uir uiu un- unb uni unn uno unr unu uob uon uoo uor ur- urb uri urn uro urr uru uun uur uuu