input: 
  def findMaxValue(nested_dict: dict) -> int:
      """ Finds the maximum integer value within a nested dictionary.
      >>> findMaxValue({"key1": {"value1": 10, "value2": 20}, "key2": {"value3": 40}})
      40
      >>> findMaxValue({"key1": {"value1": 5}, "key2": {"value2": 3}, "key3": {"value3": 8}})
      8
      """
      max_val = None
      for key, value in nested_dict.items():
          if isinstance(value, dict):
              max_val = max(findMaxValue(value), max_val)
          else:
              max_val = max(value, max_val)
      return max_val
  
output:     if max_val is None:
          return -float('inf')
      return max_val