C[C@@H](CN)CC(=O)O.C[C@@H](CN)CC(=O)O.O=S(=O)(O)c1cccc2c(S(=O)(=O)O)cccc12
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?