CCOC(=O)C(C)(NC(=O)c1ccc(NCc2ccc3nc(NC(=O)c4ccccc4)nc(NC(=O)c4ccccc4)c3c2)cc1)C(=O)OCC
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?