O=c1/c(=C/c2ccc([N+](=O)[O-])o2)sc2n1[C@@H](c1ccc(Cl)cc1)C=C(c1cc(F)c(Cl)cc1Cl)N=2
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?