COC(=O)C1=C(O)C(C(=O)OC)[C@]2(O)[C@H](C(=O)OC)[C@H]1C[C@@H](c1ccc(Cl)cc1)[C@H]2C(=O)OC
Heavy atom refers to any atom that is not hydrogen. The heavy atoms in molecules are carbon, oxygen, nitrogen, and sulfur. How many heavy atoms are in the molecule?