Parse this person name:

Siem Mercks, 1253-1323, flourished 1283-1309
user
first_name: Siem
last_name: Mercks
middle_names: []
temporal:
- start: 1253
  end: 1323
  type: life_span
- start: 1283
  end: 1309
  type: flourished
titles: []
extra_info: []
assistant