COc1ccc(C2=CC(c3ccc4c(c3)OCO4)c3c(c4ccccc4oc3=O)O2)cc1OC
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?