input: def findMaxValue(nested_dict):
      """ Given a nested dictionary, this function recursively traverses the dictionary 
      to find and return the maximum value.
      >>> findMaxValue({
      ... "key1": {
      ...     "value1": 10,
      ...     "value2": 20
      ... },
      ... "key2": {
      ...     "value3": 40
      ... },
      ... })
      40
      >>> findMaxValue({
      ... "a": 5,
      ... "b": {"c": {"d": 15, "e": 25}},
      ... "f": 10
      ... })
      25
      """
      
      max_val = None
      for value in nested_dict.values():
          if isinstance(value, dict):
              max_val = max(findMaxValue(value), max_val)
          else:
              max_val = max(value, max_val)
      return max_val
output:     max_val = None
      for value in nested_dict.values():
          if isinstance(value, dict):
              max_val = max(findMaxValue(value), max_val)
          else:
              max_val = max(value, max_val)
      return max_val