O=C(O)CN(CC(=O)O)Cc1cc2c(cc1O)Oc1cc(O)c(CN(CC(=O)O)CC(=O)O)cc1C21OC(=O)c2ccccc21
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?