O=C1C[C@@H](C(=O)OCc2ccccc2)NC(=O)C[C@@H](C(=O)OCc2ccccc2)NC(=O)C[C@@H](C(=O)OCc2ccccc2)N1
A rotatable bond is defined as any single non-ring bond, attached to a non-terminal, non-hydrogen atom. How many bonds in the molecule are rotatable?