input: def get_max_min(lst):
      """ 
      Write a Python function to get the maximum and minimum values in a given list.
      >>> get_max_min([1, 2, 3, 4, 5])
      (1, 5)
      >>> get_max_min([-1, -2, -3, -4, -5])
      (-5, -1)
      >>> get_max_min([0, 0, 0, 0])
      (0, 0)
      """
output:     return (min(lst), max(lst))