CCOC(=O)c1c(N2CCCC2)[nH]c(=O)c(C(c2ccco2)c2c(O)c(C(=O)OCC)c(N3CCCC3)[nH]c2=O)c1O
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?