input: def find_smallest_number(numbers: List[int]) -> int:
      """ Finds the smallest number in a given list of numbers.
      >>> find_smallest_number([5, 4, 12, 17, 9])
      4
      >>> find_smallest_number([3, 7, 2, 8, 1])
      1
      """
      smallest = numbers[0]
      for num in numbers:
          if num < smallest:
              smallest = num
      return smallest
output:     smallest = numbers[0]
      for num in numbers:
          if num < smallest:
              smallest = num
      return smallest