['CCO', 'Cc1[nH]c(CF)c(C=O)c1C', 'CC', 'Cc1[nH]c(CF)c(C(=O)O)c1C', 'CCOC=O', 'Cc1cc(CF)[nH]c1C', 'CF', 'CCOC(=O)c1c[nH]c(C)c1C']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cc[nH]c1.