O=C(C[C@@H]1C[C@H]2c3cc(NC(=O)c4cccnc4)ccc3O[C@H]2[C@H](CO)O1)NCc1ccc(Oc2ccccc2)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?