O=C1N=C(NNC(=O)c2cccc3ccccc23)S/C1=C\c1ccccc1OCc1ccccc1
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?