O=C(/C=C/c1ccc(O)c(O)c1)OC1C(O)CC(OC(=O)/C=C/c2ccc(O)c(O)c2)(C(=O)O)CC1O
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?