CCCC(=O)O[C@@H]1CCC2(C)C=CC([C@@H](C)C(=O)OC)=C(O2)[C@@H]2[C@]1(C)[C@@H](OC(C)=O)CC1O[C@@]12C
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?