input: Write a python function to find the maximum and minimum of two given numbers.
  assert max_and_min(10, 5) == (10, 5)
  assert max_and_min(-1, 1) == (1, -1)
  assert max_and_min(0, 0) == (0, 0)
output: def max_and_min(a, b):
      return (max(a, b), min(a, b))