O=C1C2C3C=C4c5ccccc5N(c5ccccc5)C4(C2C(=O)N1c1ccccc1)C1C(=O)N(c2ccccc2)C(=O)C31
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?