Parse this person name:

Sil Koster (1834-1894, flourished 1861-1878)
user
first_name: Sil
last_name: Koster
middle_names: []
temporal:
- start: 1834
  end: 1894
  type: life_span
- start: 1861
  end: 1878
  type: flourished
titles: []
extra_info: []
assistant