O=C(Cc1cccc(NC(=O)C2CCCN(C(=O)C3CCC3)C2)c1)Nc1cccc(C(=O)N2CCCC2)c1
Hydrogen bond acceptor: The atom, ion, or molecule component of a hydrogen bond which does not supply the bridging (shared) hydrogen atom. How many hydrogen bond acceptors does the molecule have?