bbb bbk bbn bbo bbr bby bkb bkk bkn bko bkr bnb bnk bnn bno bnr bob bok bon boo bor boy brb brk brn bro brr bry by- byk byn byo byr kbb kbk kbn kbo kbr kkb kkk kkn kkr kky kn- knk knn kno knr kob kok kon koo kor koy krk krn kro krr kry kyn kyo kyr nbb nbk nbn nbo nbr nkk nkn nko nkr nky nnb nnk nnn nno no- nob nok non noo nor noy nrb nrk nrn nro nrr nry nyk nyn nyo nyy ob- obb obk obn obo obr oby okb okk oko okr on- onb onk onn ono onr ony oo- oob ook oon ooo oor or- orb ork orn oro orr ory oyo rbb rbk rbn rbo rbr rkb rkk rko rky rnb rnn rno rnr rny rob rok ron roo ror roy rrb rrk rrn rrr ry- ryk ryn ryo ryr ryy ybr yby ykk ykn ynk ynn yny yob yok yon yoo yor yoy yrn yro yyb yyy