A hydroxy compound $(X)$ with molar mass $122\,\text{g mol}^{-1}$ is acetylated with acetic anhydride, using a large excess of the reagent ensuring complete acetylation of all hydroxyl groups. The product obtained has a molar mass of $290\,\text{g mol}^{-1}$. The number of hydroxyl groups present in compound $(X)$ is ___.