bbb bbi bbn bbo bbs bi- bib bii bin bio bis bnb bni bnn bno bns bob boi bon boo bos bsb bsi bsn bso bss ibb ibi ibn ibo ibs iib iii iin iio iis in- inb ini inn ino ins io- iob ioi ion ioo ios is- isb isi isn iso iss n-i nbb nbi nbn nbo nbs nib nii nin nio nis nnb nni nnn nno nns no- nob noi non noo nos nsb nsi nsn nso nss o-i ob- obb obi obn obo obs oib oii oin oio ois on- onb oni onn ono ons oo- oob ooi oon ooo oos os- osb osi osn oso oss sbb sbi sbn sbo sbs sib sii sin sio sis snb sni snn sno sns sob soi son soo sos ss- ssb ssi ssn sso sss