O=[N+]([O-])c1ccc2c(Nc3ccccc3-c3ccccc3Nc3c4ccccc4nc4cc([N+](=O)[O-])ccc34)c3ccccc3nc2c1
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?