Parse this person name:

Sigurd Jäntsch (1222-1285, flourished 1249-1274)
user
first_name: Sigurd
last_name: Jäntsch
middle_names: []
temporal:
- start: 1222
  end: 1285
  type: life_span
- start: 1249
  end: 1274
  type: flourished
titles: []
extra_info: []
assistant