O=C1/C(=C\c2ccc(Cl)cc2Cl)Sc2scc(-c3cccc([N+](=O)[O-])c3)[n+]21.[Cl-]
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?