bbbb bbci bbrc bcbc bccc bcci bcor bibb bibi bibo bicc bici bico bio- bioc bioi birb biri biro birr bobb bobi bobo boco boi- boii boob booc boor bor- bori boro borr brcb bric brio brob broc broo bror brrr c-bo cbbc cbcc cbcr cbir ccbc cccb cccc ccci ccic ccii ccir ccob ccoc ccrc ccri cibc cibi cibo cicc cici cico cicr ciii ciob cior cirb circ ciri ciro cirr cobb cobi cobo coco coir coob cor- corb corc cori coro corr crbc crcc crcr crib cric crob croc croo cror ibrc ibri ibro icbc iccb iccc icci icco iccr icoc icor icrc icrr iiii iiio iioi iioo iirc iobi ioci ioii ioio iooi iooo iori ircc iri- iric irio irob iroc irrc irri obbo oboi obor obri obro ocbc occc occi ocro ocrr oici oiii oobi oocr oooo orbb orbi orbo orci orco ori- oric orio oro- oror orri orro rbbb rbbr rcbc rcbo rccb rccc rcic rib- ribo ricc rico riri rob- robb robi robo rocc roco roio roir roob rooi roor rorc rori roro rrrr