O=C(c1ccccc1)c1nnn(Cc2ccccc2Cn2nnc(C(=O)c3ccccc3)c2C(=O)c2ccccc2)c1C(=O)c1ccccc1
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?