O=C1CN(/N=C\c2ccc(-c3ccc([N+](=O)[O-])cc3)o2)C([O-])=N1.[Na+]
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?