Parse this person name:

Demi de Heer (1904-1971, flourished 1920-1945)
user
first_name: Demi
last_name: de Heer
middle_names: []
temporal:
- start: 1904
  end: 1971
  type: life_span
- start: 1920
  end: 1945
  type: flourished
titles: []
extra_info: []
assistant