bbb bbi bbn bbo bbr bbs bi- bib bii bin bio bir bis bnb bni bnn bno bnr bns bob boi bon boo bor bos brb bri brn bro brr brs bsb bsi bsn bso bsr bss ibb ibi ibn ibo ibr ibs iib iii iin iio iir iis in- inb ini inn ino inr ins io- iob ioi ion ioo ior ios ir- irb iri irn iro irr irs is- isb isi isn iso isr iss n-i nbb nbi nbn nbo nbr nbs nib nii nin nio nir nis nnb nni nnn nno nns no- nob noi non noo nor nos nrb nri nrn nro nrr nrs nsb nsi nsn nso nsr nss o-i ob- obb obi obn obo obr obs oib oii oin oio oir ois on- onb oni onn ono onr ons oo- oob ooi oon ooo oor oos or- orb ori orn oro orr ors os- osb osi osn oso osr oss rbb rbi rbn rbo rbr rbs rib rii rin rio rir ris rnb rni rnn rno rnr rns rob roi ron roo ror ros rrb rri rrn rrr rrs rsb rsi rsn rso rsr rss sbb sbi sbn sbo sbr sbs sib sii sin sio sir sis snb sni snn sno snr sns sob soi son soo sor sos sr- srb sri srn sro srr srs ss- ssb ssi ssn sso ssr sss