[O-][Cl+3]([O-])([O-])[O-].c1ccc(-c2ccc(-c3n(-c4ccccn4)c4ccccc4[n+]3-c3ccccn3)cc2)cc1
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?