input: Write a function to find the minimum and maximum values in a list.
  assert min_max([3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5]) == (1, 9)
  assert min_max([-10, 0, 10, 20, -20, 30, -30]) == (-30, 30)
  assert min_max([5, 7, 2, 8, 3, 6, 4, 1, 9, 0]) == (0, 9)
output: def min_max(lst):
      return (min(lst), max(lst))