Carboxylic Acids And Its Derivatives

Identify the product formed in the following reaction.
$\mathrm{C}_6 \mathrm{H}_5-\mathrm{CH}_2-\mathrm{CH}_3 \xrightarrow[\text { ii) } \mathrm{H}_3 \mathrm{O}^{+}]{\text {i) alk. } \mathrm{KMnO}_4}$ Product