COC(=O)C1=C(OC(=O)/C=C/c2ccc(Cl)cc2)C(C(=O)OC)[C@]2(O)[C@@H](C(=O)OC)[C@H]1C[C@@H](c1ccccc1)[C@@H]2C(=O)OC
Heavy atom refers to any atom that is not hydrogen. How many heavy atoms do the molecule have?