input: 
  def get_max_min(lst):
      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)
  
  # Example:
  # get_max_min([1, 2, 3, 4, 5]) == (1, 5)
  # get_max_min([-10, 0, 100, -50]) == (-50, 100)
  
output:     return (min_value, max_value)