O=C1C[C@@H]2[C@@H](c3ccccc3)[C@@H]3C(=O)c4ccccc4NC(=O)[C@H]3[C@]2(O)c2ccccc2N1
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?