Given an array of integers arr, a lucky integer is defined as an integer whose frequency in the array is equal to its value.

Return the largest lucky integer in the array. If no lucky integer exists, return $-1$.

Constraints:

• $1 \leq$ arr.length $\leq 500$

• $1 \leq$ arr[i] $\leq 500$

Now, let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Implement your solution in the following coding playground.