O=C(O)C1CCN(C(=O)c2ccccc2N2C(=O)[C@@H]3Cc4c([nH]c5ccccc45)C(c4cccc(Cl)c4)N3C2=O)CC1
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?