bbbb bbdd bbdo bbrc bcbc bccc bcor bd-r bdbc bddc bobb bobo boco bodb bodo boob booc bood boor bor- bord boro borr brcb brdo brob broc brod broo bror brrr c-bo c-cd cbbc cbcc cbcr cbdb cbdc cbdo cbrd ccbc cccb cccc ccdc ccdr ccob ccoc ccod ccrc cd-r cddb cddr cobb cobo coco codd coob cood cor- corb corc cord coro corr crbc crcc crcr crdc crob croc crod croo cror d-bo dbcc dcbc dccb dccc dcdb dddd ddoc ddrc dobb doco dod- dodd dodo doob dood door dorc dord doro dorr drbc drob drod obbo obor obro ocbc occc ocro ocrr odbo oddd odoo odor oocr oooo oord orbb orbo orco ordo oro- oror orro rbbb rbbr rcbc rcbo rccb rccc rcdc rcrd rdoc rob- robb robo rocc roco rodd rodo roob rood roor rorc roro rrrr