C#CCOCCOCCOCCNc1nc(N2CCOCC2)nc(N2CCN(C(=O)CCCCCCCCCCNC(=O)[C@H](CO)n3cc(CCCSC)nn3)CC2)n1
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?