O=C1OC2(c3cc(Br)c(O)c(Br)c3Oc3c2cc(Br)c(O)c3Br)c2c(Cl)c(Cl)c(Cl)c(Cl)c21
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?