The compound shown is heated with excess hot alkaline $\mathrm{KMnO}{}_4$ and then acidified. How many carboxylic acid groups are present in the final organic product? Give the answer as an integer.

The compound shown is 1-tert-butyl-3-isopropyl-5-methylbenzene. The methyl and isopropyl groups each have a benzylic hydrogen and each become a $\mathrm{COOH}$ group. The tert-butyl group has none and is unchanged. The product, 5-tert-butylbenzene-1,3-dicarboxylic acid, has 2 carboxylic acid groups.