C#CCOCCOCCOCCNc1nc(N2CCOCC2)nc(N2CCN(C(=O)[C@H](Cc3cc4ccccc4[nH]3)n3cc([C@@H](N)C(C)CC)nn3)CC2)n1.Cl
Hydrogen bond acceptor is the chemical compound which contains the lone electron pairs that participate in the hydrogen bond formation. How many hydrogen bond acceptors does the molecule contain?