function maxMin(k, arr) {
  // sort - lowest to highest
  arr.sort((a, b) => a - b);

  // calculate unfairness of "first chunk" of size k
  let minUnfairness = arr[k - 1] - arr[0];

  for (let i = 1; i + k - 1 < arr.length; i++) {
    // calculate unfairness in "next chunk" of size k
    const unfairness = arr[i + k - 1] - arr[i];

    if (unfairness < minUnfairness) {
      minUnfairness = unfairness;
    }
  }

  return minUnfairness;
}