O=C1C=CC2(O[C@H](c3ccccc3)[C@@H](c3ccccc3)O2)C(SC(=O)c2ccccc2)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?