['O=Cc1ccc(F)cc1', 'CC(C)NC(=S)NCCN', 'CCC', 'NC(=S)NCCNC(=O)c1ccc(F)cc1', 'CC(C)NC(N)=S', 'CCNC(=O)c1ccc(F)cc1', 'CCNC(=S)NC(C)C', 'NC(=O)c1ccc(F)cc1', 'Fc1ccccc1', 'CC(C)NC(=S)NCCNC=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.