CC1(O)CC2(O)C=CC3=C(C(=O)c4cccc(O)c4C3=O)C2(O)C(=O)C1O
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?