input: from typing import List
  
  def find_smallest_number(nums: List[int]) -> int:
      """ Given a list of integers, find and return the smallest number.
      >>> find_smallest_number([4, 5, 6, 7, 8])
      4
      >>> find_smallest_number([9, 2, 4, 1, 5])
      1
      """
output:     if not nums:
          raise ValueError("The list is empty")
      smallest = nums[0]
      for num in nums:
          if num < smallest:
              smallest = num
      return smallest