Parse this person name:

Alexander R. Shelly John Krueger, Parkston, flourished 1870-1903
user
first_name: Alexander
last_name: Krueger
middle_names:
- R.
- Shelly
- John
temporal:
- start: 1870
  end: 1903
  type: flourished
titles: []
extra_info:
- Parkston
assistant