O=C(Nc1c2c(nn1-c1cccc(Cl)c1)C[S+]([O-])C2)c1ccc2c(c1)OCO2
A rotatable bond is defined as any single non-ring bond, attached to a non-terminal, non-hydrogen atom. Amide C-N bonds are not counted because of their high barrier to rotation.  How many rotatable bonds does the molecule have?