Parse this person name:

Sam van der Horst, 1223-1285, flourished 1241-1251
user
first_name: Sam
last_name: van der Horst
middle_names: []
temporal:
- start: 1223
  end: 1285
  type: life_span
- start: 1241
  end: 1251
  type: flourished
titles: []
extra_info: []
assistant