Valproic acid, used to treat seizures and bipolar disorder, is composed of C, H, and O

Valproic acid, used to treat seizures and bipolar disorder, is composed of C, H, and O. A 0.165-g sample is combusted to produce 0.166 g of water and 0.403 g of carbon dioxide.
a. What is the empirical formula for valproic acid?
b. If the molar mass is 144 g/mol, what is the molecular formula?