bbbb bblb bbpr blno blob blon bloo blop bnor bnpp bnrr bobb bobo boll boln bolo bonn bono boob bool boon boop boor bopp bor- born boro borr brlp brno brob brol bron broo bror brrr lblr llll lloo lnbp lob- lobb lobo loll lolo lono lonr loob lool loon loop loor lopp lorn loro lppl lprp lron lrrr nbbo nbpp nlrb nlrp nnnn nnpr nobo noll nolo nolp non- nonn nono noo- noob nool noon nooo noop noor nor- norb norn noro norr npbl nppl nrlb nron nrpn nrrl obbo obol obon obor obro olbo ollo olon olor onno onon onor oolo oooo opo- opon opor oppo orbb orbo orlo orno oro- oron oror orro plbr plob plon ploo plop plpp pnln pnnl pnon pnpo pnpp pnro pobo poll polo pono ponp pool poon poop poor pop- popo popp porb porn poro porr pplo pppn pppo pppp prlr prnp pro- prob prol pron proo prop rbbb rbbr rnbr rob- robb robo roll rolo rolp rono roob rool roon roop roor ropo roro rpob rpon rppn rrrr