['C#CCN', 'Cc1oc(-c2cccs2)nc1CC=O', 'C#CC', 'Cc1oc(-c2cccs2)nc1CC(N)=O', 'C#CCNC(C)=O', 'Cc1cnc(-c2cccs2)o1', 'c1ccsc1', 'C#CCNC(=O)Cc1ncoc1C']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1csc(-c2ncco2)c1.