O=[N+]([O-])c1cccc(/C(O)=C(/C([S-])=Nc2ccccc2)[n+]2ccccc2)c1
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?