def max_min(k, arr):
    #Time complexity: O(n*log(n))
    #Space complexity (ignoring input): O(1)
    arr.sort()
    minimum_unfairness = arr[k - 1] - arr[0]
    for index in range(1, len(arr) - k + 1):
        if minimum_unfairness > arr[index + k - 1] - arr[index]:
            minimum_unfairness = arr[index + k - 1] - arr[index]

    return minimum_unfairness