input: 
  def find_smallest_number(numbers: List[int]) -> int:
      """ Find and return the smallest number in the given list of numbers.
      >>> find_smallest_number([5, 4, 12, 17, 9])
      4
      >>> find_smallest_number([10, 20, 5, 2, 30])
      2
      """
      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