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