O=C1C2C3C=C4c5ccccc5N(c5ccccc5)C4(C2C(=O)N1c1ccccc1)C1C(=O)N(c2ccccc2)C(=O)C31
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?