bbb bbi bbk bbn bbo bi- bib bii bik bin bio bkb bkk bkn bko bnb bni bnk bnn bno bob boi bok bon boo ibb ibi ibk ibn ibo iib iii iin iio ikb iki ikk iko in- inb ini ink inn ino io- iob ioi ion ioo kbb kbi kbk kbn kbo kib kii kik kin kio kkb kki kkk kkn kn- kni knk knn kno kob koi kok kon koo n-i nbb nbi nbk nbn nbo nib nii nik nin nio nki nkk nkn nko nnb nni nnk nnn nno no- nob noi nok non noo o-i ob- obb obi obk obn obo oib oii oik oin oio okb oki okk oko on- onb oni onk onn ono oo- oob ooi ook oon ooo