input: 
  def maximum(arr, k):
      """
      Given an array arr of integers and a positive integer k, return a sorted list 
      of length k with the maximum k numbers in arr.
  
      Example 1:
  
          Input: arr = [-3, -4, 5], k = 3
          Output: [-4, -3, 5]
  
      Example 2:
  
          Input: arr = [4, -4, 4], k = 2
          Output: [4, 4]
  
      Example 3:
  
          Input: arr = [-3, 2, 1, 2, -1, -2, 1], k = 1
          Output: [2]
  
      Note:
          1. The length of the array will be in the range of [1, 1000].
          2. The elements in the array will be in the range of [-1000, 1000].
          3. 0 <= k <= len(arr)
      """
  
output:     arr.sort()
      return arr[-k:]