CC1(C)C(=O)CC[C@]2(C)C3=C(CC[C@@H]12)C[C@]1(C)CC[C@H]2C(C)(C)C(=O)CC[C@]2(C)[C@H]1CC3
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?