bbbb bnor bnrr bobb bobo bokn boko bonk bonn bono boob book boon boor bor- bork born boro borr brkb brno brob brok bron broo bror brrr kbbb kbbk kbbo kbbr kbkb kbkk kbko kbkr kbnn kbno kbnr kbob kbok kbon kboo kbrb kbrk kbrn kbro kkbb kkbn kkbo kkbr kkkk kknb kknn kkno kkob kkon kkoo kkor kkrb kkrk kkrn kkro kkrr knbb knbn knbr knkk knnb knnk knnr knob knok knon knor knrb knrk knro kobb kobk kobn kobo kobr kokb kokk kokn koko kokr konk kono koob kook koon kooo koor korb kork korn koro korr krbb krbk krbr krkk krkn krko krkr krnb krnk krnn krno krob krok kroo kror krrb krrk krrn krro krrr nbbo nkok nkor nnnn nobo noko non- nonn nono noo- noob nook noon nooo noor nor- norb nork norn noro norr nron obbo obkb obok obon obor obro okko okno okok okon okor okro onno onon onor oooo orbb orbo orko orno oro- orok oron oror orro rbbb rbbr rnbr rob- robb robo rokk roko rokr ronk rono roob rook roon roor rork roro rrrr