['CC(=O)/N=c1/sccn1C', 'c1ccc(-c2nccs2)nc1', 'c1ccncc1', 'Cn1ccs/c1=N/C(=O)Cc1cscn1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(Cc1csc(-c2ccccn2)n1)/N=c1\[nH]ccs1.