input: 
  def find_largest_number(lst: List[int]) -> int:
      """ Finds the largest number in a given list of integers.
      >>> find_largest_number([1000, 506, 299, 620, 35])
      1000
      """
  
output:     if not lst:
          raise ValueError("List is empty")
      largest = lst[0]
      for num in lst:
          if num > largest:
              largest = num
      return largest