input: Write a python function to find the maximum and minimum numbers in a list.
  assert find_max_min([1, 2, 3, 4, 5]) == (5, 1)
  assert find_max_min([10, 20, 30, 40, 50]) == (50, 10)
  assert find_max_min([-10, -20, -30, -40, -50]) == (-10, -50)
output: def find_max_min(lst):
      return max(lst), min(lst)