CCN1CCN(C(=O)NC(C(=O)NC2C(=O)N3C(C(=O)[O-])=C(CSc4nnnn4C)CSC23)c2ccc(O)cc2)C(=O)C1=O.[Na+]
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?