O=C1OCCN1C(=O)[C@H]1[C@H](c2ccc([N+](=O)[O-])cc2)C(c2ccc(F)cc2)=NN1c1ccc(Br)cc1
The donor in a hydrogen bond is usually a strongly electronegative atom such as N, O, or F that is covalently bonded to a hydrogen bond. How many hydrogen bond donors does the molecule have?