['C/C=C/C=C/C=O', 'NC(=O)Nc1ccc(N)cc1', 'NC=O', 'C/C=C/C=C/C(=O)Nc1ccc(N)cc1', 'C/C=C/C=C/C(N)=O', 'NC(=O)Nc1ccccc1', 'NC(N)=O', 'C/C=C/C=C/C(=O)Nc1ccccc1', 'CC', 'C/C=C/C(=O)Nc1ccc(NC(N)=O)cc1', 'C/C=C/C', 'CC(=O)Nc1ccc(NC(N)=O)cc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.