O=c1c(OC2OC(CO)C(O)C(O)C2OC2OC(CO)C(O)C(O)C2O)c(-c2ccc(O)cc2)oc2cc(O)cc(O)c12
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?