COC(=O)[C@@]1(Cc2ccccc2)[C@H]2c3cc(C(=O)N(C)C)n(CCO)c3C[C@H]2CN1C(=O)c1ccccc1
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?