Parse this person name:

Alexander Ariens (1299-1349, flourished 1326-1344)
user
first_name: Alexander
last_name: Ariens
middle_names: []
temporal:
- start: 1299
  end: 1349
  type: life_span
- start: 1326
  end: 1344
  type: flourished
titles: []
extra_info: []
assistant