O=[N+]([O-])c1ccc(S[C@H]2[C@H]3C[C@@H](Cl)[C@@H]2c2c(-c4ccccc4)[nH]c(-c4ccccc4)c23)cc1
Hydrogen bond acceptor is the chemical compound which contains the lone electron pairs that participate in the hydrogen bond formation. This compound should contain a more electronegative atom (more electronegative than hydrogen) with lone electron pairs. Then it can attract protons from a donor. Moreover, the electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?