COC(=O)C1OC(=O)C2OC23[C@@]1(C)CCC1[C@@]3(C)C(OC(C)=O)CC2C(C)(C)C(=O)CC[C@@]21C
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?