O=C1C=CC(=O)c2c1ccc1c3ccccc3n(CCCCCCCCn3c4ccccc4c4ccc5c(c43)C(=O)C=CC5=O)c21
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?