Parse this person name:

Dirk van Dokkum (1231-1282, flourished 1251-1267)
user
first_name: Dirk
last_name: van Dokkum
middle_names: []
temporal:
- start: 1231
  end: 1282
  type: life_span
- start: 1251
  end: 1267
  type: flourished
titles: []
extra_info: []
assistant