O=C(NCCN(CCNC(=O)c1nc[nH]c1C(=O)Nc1ccc(Cl)cc1)CCNC(=O)c1nc[nH]c1C(=O)Nc1ccc(Cl)cc1)c1nc[nH]c1C(=O)Nc1ccc(Cl)cc1
All atoms other than hydrogen are referred to be heavy atoms. How many heavy atoms are there in the molecule?