['C=CCN', 'C[C@@H](NC=O)c1ccc(Cl)c(Cl)c1', 'C=CCNC=O', 'C[C@@H](N)c1ccc(Cl)c(Cl)c1', 'C=CC', 'C[C@@H](NC(N)=O)c1ccc(Cl)c(Cl)c1', 'C=CCNC(N)=O', 'CCc1ccc(Cl)c(Cl)c1', 'Clc1ccccc1Cl', 'C=CCNC(=O)NCC']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.