['O=C(CO)NCC(F)(F)F', 'O=Cc1ccc2c3c(cccc13)CC2', 'NCC(F)(F)F', 'O=CCOC(=O)c1ccc2c3c(cccc13)CC2', 'CC(=O)NCC(F)(F)F', 'O=C(O)c1ccc2c3c(cccc13)CC2', 'CC(F)(F)F', 'NC(=O)COC(=O)c1ccc2c3c(cccc13)CC2', 'O=COCC(=O)NCC(F)(F)F', 'c1cc2c3c(cccc3c1)CC2']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cc2c3c(cccc3c1)CC2.