Parse this person name:

Marie Gabriel Théodore G. Blanc, Marquesnec, 1818-1849
user
first_name: Marie
last_name: Blanc
middle_names:
- Gabriel
- Théodore
- G.
temporal:
- start: 1818
  end: 1849
  type: life_span
titles: []
extra_info:
- Marquesnec
assistant