input: def find_smallest_number(numbers: List[int]) -> int:
      """ Find the smallest number in the given list.
      >>> find_smallest_number([5, 4, 12, 17, 9])
      4
      >>> find_smallest_number([7, 2, 9, 3, 10])
      2
      """
output:     if not numbers:
          raise ValueError("List is empty")
      smallest = numbers[0]
      for num in numbers:
          if num < smallest:
              smallest = num
      return smallest