input: def findMaxValue(nested_dict: dict) -> int:
      """Find the maximum value within a nested dictionary.
      >>> sample_dict = {
      ...     "key1": {
      ...         "value1": 10,
      ...         "value2": 20
      ...     },
      ...     "key2": {
      ...         "value3": 40
      ...     },
      ... }
      >>> findMaxValue(sample_dict)
      40
      """
output:     max_value = float('-inf')
      for key, value in nested_dict.items():
          if isinstance(value, dict):
              max_value = max(max_value, findMaxValue(value))
          else:
              max_value = max(max_value, value)
      return max_value