O=C(C[C@@H]1C/C=C\C[C@H](NC(=O)OCC2c3ccccc3-c3ccccc32)C(=O)OC[C@@H]2CCCN2C1=O)NCCO
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?