O=S(=O)(c1ccc(/N=C2\NC(c3ccc(O)cc3)(c3ccccc3O)c3ccccc32)cc1)c1ccc(/N=C2/NC(c3ccc(O)cc3)(c3ccccc3O)c3ccccc32)cc1
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?