COC(=O)[C@H]1C=C[C@H](OC2OC(COC(C)=O)C(OC(C)=O)C(OC(C)=O)C2OC(C)=O)n2c(=O)n(-c3ccccc3)c(=O)n21
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?