C[C@]12C(=O)N(c3cccc(Cl)c3)C(=O)N1[C@H]1c3ccccc3OC[C@@H]1[C@H]2c1ccccc1
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?