COC(=O)c1cc2c3c(cc(NCCN)c2[nH]1)N(C(=O)c1cc2cc(OC)c(OC)c(OC)c2[nH]1)CC3CCl.Cl
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?