bbbb bbci bbrc bcbc bccc bcci bcit bcor bctc bibb bibi bibo bicc bici bico bio- bioc bioi biot birb biri biro birr birt bitc bito bitt bobb bobi bobo boco boi- boii boit boob booc boor boot bor- bori boro borr bort botb boti boto bott brcb bric brio brit brob broc broo bror brot brrr brtc btcc btob btor btrc btrt bttb c-bo cbbc cbcc cbcr cbct cbir cbit cbot cbrt cbtc ccbc cccb cccc ccci ccic ccii ccir ccob ccoc ccrc ccri ccrt cctb cctc cctt cibc cibi cibo cicc cici cico cicr cict ciii ciit ciob cior cirb circ ciri ciro cirr cirt citb citi cito citt cobb cobi cobo coco coct coir coit coob coot cor- corb corc cori coro corr cort cotb cotc coti coto cott crbc crcc crcr crib cric crit crob croc croo cror crot crrt crtc ctbi ctic ctor ctot ctrc ibot ibrc ibri ibro ibtb ibtc icbc iccb iccc icci icco iccr icct icoc icor icrc icrr icrt iiii iiio iiit iioi iioo iirc iitr iitt iobi ioci ioii ioio ioit iooi iooo iori ioto ircc iri- iric irio irob iroc irrc irri irti itic itoi itoo itor itri itto obbo obit oboi obor obot obri obro ocbc occc occi occt ocro ocrr oct- octi octo oici oiii oirt oitc oiti oobi oocr oooo oort ootb orbb orbi orbo orci orco ori- oric orio orit oro- oror orot orri orro ortc orto otic otit oto- otoo otor otro otti otto rbbb rbbr rcbc rcbo rccb rccc rcic rctc rcti rib- ribo ricc rico rict riot riri riti rito ritt rob- robb robi robo robt rocc roco roio roir roit roob rooi roor root rorc rori roro rort rotc roti roto rotr rott rrrr rtcc tbcb tbcc tbit tbrb tccc tctc tibi ticc tico tiit tirb tiri tiro tirr titc titi tito titt tobi tobo tobt toci toco toit toor toot torc tori toro torr tort totc toti toto totr tott trcc tri- trib tric trio trit troc troi troo trot trtc trtr ttbb tttt