O=c1c2cc(S(=O)(=O)Nc3c(Cl)cccc3Cl)ccc2ncn1NS(=O)(=O)c1ccc2ccccc2c1
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?