Parse this person name:

Janna van Beaumont (1920-1991, flourished 1950-1962)
user
first_name: Janna
last_name: van Beaumont
middle_names: []
temporal:
- start: 1920
  end: 1991
  type: life_span
- start: 1950
  end: 1962
  type: flourished
titles: []
extra_info: []
assistant