C#CCOCCOCCOCCNc1nc(N2CCOCC2)nc(N2CCN(C(=O)[C@H]([C@@H](C)CC)n3cc(CCCCN)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?