COC(=O)C1=C(C(=O)OC)C23CC1C1C(C(=O)OC)=C(C(=O)OC)C12C1C=CC3C2C(=O)OC(=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?