O=C1C2C(C(=O)N1c1ccccc1)C1(Br)c3ccccc3C2(Br)C2C(=O)N(c3ccccc3)C(=O)C21
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?