C#CCOCCOCCOCCNc1nc(N2CCOCC2)nc(N2CCN(C(=O)CCCCCCCCCCNC(=O)[C@H](CO)n3cc(CCCCCN)nn3)CC2)n1
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?