bbbb bbrc bcbc bccc bcor bctc bnoc bnor bnrr bobb bobo boco bonc bonn bono bont boob booc boon boor boot bor- born boro borr bort botb botn boto bott brcb brno brob broc bron broo bror brot brrr brtc btcc btob btor btrc btrt bttb c-bo cbbc cbcc cbcn cbcr cbct cbot cbrn cbrt cbtc ccbc ccbn cccb cccc ccnb ccnc ccnr ccob ccoc ccrc ccrt cctb cctc cctt cnbc cnco cnrc cnrr cnrt cntc cntr cobb cobo coco coct con- conc conn cono cont coob coon coot cor- corb corc corn coro corr cort cotb cotc cotn coto cott crbc crcc crcr crob croc cron croo cror crot crrt crtc ctor ctot ctrc ctrn cttn nbbc nbbo nbcc nbco ncbc nccc nccn nccr ncct ncnc ncoc ncor ncrc nctc nctr nnnn nnot nntn nobc nobo noco noct non- nonn nono nont noo- noob noon nooo noor noot nor- norb norc norn noro norr nort not- noto nott nroc nron nrrc ntbc ntcc ntrc ntto nttr obbo obon obor obot obro ocbc occc occn occt ocon ocro ocrr oct- octo onc- onco onct onno onon onor ont- ontc onto oocr oont oooo oort ootb orbb orbo orco ornc orno oro- oron oror orot orro ortc orto oto- oton otoo otor otro otto rbbb rbbr rcbc rcbo rccb rccc rcnr rcon rctc rnbr rnco rnnt rnot rob- robb robo robt rocc roco ronc rono ront roob roon roor root rorc roro rort rotc rotn roto rotr rott rrrr rtcc tbcb tbcc tbrb tccc tcnn tcon tctc tnbc tncc tobo tobt toco tonb tonn tono toon toor toot torc torn toro torr tort totc toto totr tott trcc trno troc tron troo trot trtc trtr ttbb ttcn tton tttt