COc1c(CC(=O)c2cc3c(cc2O)OC(C)(C)C(O)C3)ccc2c1C=CC(C)(C)O2
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?