bbbb bbox bnor bnrr bobb bobo bonn bono bont boob boon boor boot boox bor- born boro borr bort botb botn boto bott brno brob bron broo bror brot brox brrr btob btor btrt bttb nbbo nnnn nnot nntn nobo non- nonn nono nont nonx noo- noob noon nooo noor noot nor- norb norn noro norr nort not- noto nott nron ntto nttr obbo obon obor obot obox obro onno onon onor ont- onto oont oooo oort ootb orbb orbo orno oro- oron oror orot orro orto oto- oton otoo otor otro otto oxo- oxon oxox oxxo rbbb rbbr rnbr rnnt rnot rob- robb robo robt rono ront roob roon roor root roox roro rort rotn roto rotr rott roxo rrrr tbox tbrb tobo tobt tonb tonn tono toon toor toot torn toro torr tort torx toto totr tott tox- toxo toxt trno tron troo trot trox trtr ttbb tton tttt txtr xbox xorn xoro xoxo xtro xxxo xxxx