COc1cc(OC2OC(CO)C(O)C(O)C2O)c2c(O)c3c(=O)cc(C)oc3cc2c1
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?