Parse this person name:

Heuser Walter, Petros M. Berndt Hanns, 1826-1903
user
first_name: Petros
last_name: Heuser Walter
middle_names:
- M.
- Berndt
- Hanns
temporal:
- start: 1826
  end: 1903
  type: life_span
titles: []
extra_info: []
assistant