bbbb bbbs bbrc bcbc bcbs bccc bccs bcor bcos bcrs bcsc bcss bobb bobo bobs boco bocs boob booc boor boos bor- boro borr bors bosc boso boss brcb brob broc broo bror bros brrr brrs brsb brsr bscs bsos bssc c-bo cbbc cbbs cbcc cbcr cbcs cbsc ccbc cccb cccc cccs ccob ccoc ccrc ccrs ccss cobb cobo cobs coco coob coos cor- corb corc coro corr cors cosc coso coss crbc crcc crcr crob croc croo cror crss cscb cscc csco cscr cscs csob csor csos csrc csrs cssr obbo obor obos obro obsr obss ocbc occc ocos ocro ocrr ocrs oocr oooo ooos orbb orbo orbs orco orcs oro- oror oros orro orrs orso oscc osco osoo osor osos osro ossb osso rbbb rbbr rbbs rbss rcbc rcbo rccb rccc rccs rcos rcsc rcss rob- robb robo robs rocc roco rocs roob roor roos rorc roro rosc roso ross rrrr rscc rscs rsos s-os sbbs sbcc sbcs sbor sccc sccs scob scoo scor scr- scrc scrs scsc scso scsr sobo sobr sobs soco socr socs soor soos sorb soro sorr sors soso soss srbc srcc sros ssbr sscc sscs ssoc ssrc ssrs sssb sssc ssss