['NC=O', 'NCCCCC(=O)NC1CCCCCCC1', 'NC1CCCCCCC1', 'NC(=O)NCCCCC=O', 'NC(N)=O', 'CCCCC(=O)NC1CCCCCCC1', 'C1CCCCCCC1', 'NC(=O)CCCCNC(N)=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1CCCCCCC1.