Parse this person name:

Denis Förster (1774-1852, flourished 1796-1821)
user
first_name: Denis
last_name: Förster
middle_names: []
temporal:
- start: 1774
  end: 1852
  type: life_span
- start: 1796
  end: 1821
  type: flourished
titles: []
extra_info: []
assistant