Definition: In this task, you will be presented with a question in Dutch language, and you have to write the person names from the question if present. B denotes the first item of a phrase and an I any non-initial word. Phrase used for the person name - PER. There can be instances with no person name entity, then return 'None'.
Input: De schaarse keren dat de Belgische vorsten eigengereid optraden , gebeurde dat wanneer ze hun eigen positie in gevaar zagen : tijdens de koningskwestie , de onafhankelijkheid van Kongo of de staatshervorming .
Output:
None