What is Z in the above sequence of reactions?

Cumene on oxidation followed by acidic hydrolysis yields phenol (X). Reaction of phenol with carbon dioxide in the presence of sodium hydroxide, followed by acidification converts phenol to $1$−hydroxybenzoic acid (Salicylic acid) (Y).This is Kolbe–Schmitt reaction. The salicylic acid then reacts with acetic anhydride (${\left({\mathrm{CH}}_3\mathrm{CO}\right)}_2\mathrm{O}$) to form aspirin (Z).