Parse this person name:

Boris Koster (1931-1986, flourished 1959-1976)
user
first_name: Boris
last_name: Koster
middle_names: []
temporal:
- start: 1931
  end: 1986
  type: life_span
- start: 1959
  end: 1976
  type: flourished
titles: []
extra_info: []
assistant