CC(=O)OCC(OC(C)=O)C(OC(C)=O)C(OC(C)=O)C(=O)CNn1c(-c2ccccc2Cl)nc2ccc(Br)cc2c1=O
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?