-ene bbbb bbeb bbet bcbc bccc bcec bcet bctc bebb bebe beeb been beet bene benn bent betc bete bett bnet btcc btec bten bttb cbbc cbcc cbce cbcn cbct cbec cbee cbet cbtc ccbc ccbn cccb cccc ccee ccnb ccnc ccne cctb cctc cctt cec- cece cect ceeb ceec cen- cene cent cet- cete cnbc cnet cntc ctec cten ctne cttn ebbc ebcc eben ecbc ecbe eccb eccc ecce ecct ecne ect- ectc eeee eent eetc eete enb- enbn ence enee ennc enne ent- ente etbc etcc etec etee eten etne ette ettn nbbc nbcc ncbc nccc nccn ncct ncec ncee ncen ncnc nctc ncte nebb nebe nebn necc nece nect neeb neen neet nene nent net- netb nete nett nnnn nntn ntbc ntcc tbcb tbcc tbce tccc tcnn tctc tect teec teen teet tenb tenc tene tenn tent tete tett tnbc tncc tneb ttbb ttcn tten tttt