Parse this person name:

Bekbergen van den Nyeuwenhuysen, Pieter Sem M. U. L., 1934-1987
user
first_name: Pieter
last_name: Bekbergen van den Nyeuwenhuysen
middle_names:
- Sem
- M.
- U.
- L.
temporal:
- start: 1934
  end: 1987
  type: life_span
titles: []
extra_info: []
assistant