Cc1ccc(S(=O)(=O)N/N=C(\C(=O)Nc2cccc([N+](=O)[O-])c2)c2nc3ccc([N+](=O)[O-])cc3nc2O)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?