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'.

Example Input: Mannen :
Example Output: None

Example Input: De combinatie van de twee ingrepen is een eerste experiment om de autokosten ' variabel ' te maken .
Example Output: None

Example Input: In de marge van Wimbledon raakte ook Damir Dokic , de vader van youngster Jelena Dokic , negatief in het nieuws .
Example Output:
Damir: B-PER, Dokic: I-PER, Jelena: B-PER, Dokic: I-PER