bbbb bcbc bccc bctc bnoc bobb bobo boco bonc bonn bono bont boob booc boon boot botb botn boto bott btcc btob bttb c-bo cbbc cbcc cbcn cbct cbot cbtc ccbc ccbn cccb cccc ccnb ccnc ccob ccoc cctb cctc cctt cnbc cnco cntc cobb cobo coco coct con- conc conn cono cont coob coon coot cotb cotc cotn coto cott ctot cttn nbbc nbbo nbcc nbco ncbc nccc nccn ncct ncnc ncoc nctc nnnn nnot nntn nobc nobo noco noct non- nonn nono nont noo- noob noon nooo noot not- noto nott ntbc ntcc ntto obbo obon obot ocbc occc occn occt ocon oct- octo onc- onco onct onno onon ont- ontc onto oont oooo ootb oto- oton otoo otto tbcb tbcc tccc tcnn tcon tctc tnbc tncc tobo tobt toco tonb tonn tono toon toot totc toto tott ttbb ttcn tton tttt