See example [here](https://sourceacademy.nus.edu.sg/playground#chap=4&ext=NONE&prgrm=MYewdgzgLgBAhjAvDANgS2gCgIwBoYBM%2BAzPgCz4Cs%2BAbPgOz4Ac%2BAnPtgAwd4zZF9SfCn2p86fRnxZ92hTgEoA3ACgAJgCc4AdwD66LHGUqgA).
