input: Write a python function to find the nth smallest number in a list.
  assert nth_smallest([3, 1, 2, 5, 4], 2) == 2
  assert nth_smallest([10, 7, 5, 8, 3], 4) == 8
  assert nth_smallest([22, 14, 3, 8, 19, 5], 1) == 3
output: def nth_smallest(numbers, n):
      sorted_numbers = sorted(numbers)
      return sorted_numbers[n - 1]