CCCC(=O)O[C@@H]1CCC2(C)C=CC([C@@H](C)C(=O)OC)=C(O2)[C@H]2[C@H](C)[C@H](O)C[C@H](OC(C)=O)[C@@]21C
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?