Parse this person name:

Oscar van Geffen (1301-1354, flourished 1316-1342)
user
first_name: Oscar
last_name: van Geffen
middle_names: []
temporal:
- start: 1301
  end: 1354
  type: life_span
- start: 1316
  end: 1342
  type: flourished
titles: []
extra_info: []
assistant