O=C(OCC(=O)N1N=C(c2ccc(Cl)cc2)CC1c1ccco1)c1cncc(Br)c1
A rotatable bond is defined as any single non-ring bond, attached to a non-terminal, non-hydrogen atom. Amide C-N bonds are not counted because of their high barrier to rotation.  How many rotatable bonds does the molecule have?