input: def get_max_min(lst):
      """Return the maximum and minimum values in a given list.
      >>> get_max_min([3, 5, 2, 8, 1])
      (1, 8)
      >>> get_max_min([10, -1, 3, 4, 0])
      (-1, 10)
      """
      min_value = lst[0]
      max_value = lst[0]
      
      for i in range(1, len(lst)):
          if lst[i] > max_value:
              max_value = lst[i]
          if lst[i] < min_value:
              min_value = lst[i]
      
      return (min_value, max_value)
output:     min_value = lst[0]
      max_value = lst[0]
      
      for i in range(1, len(lst)):
          if lst[i] > max_value:
              max_value = lst[i]
          if lst[i] < min_value:
              min_value = lst[i]
      
      return (min_value, max_value)