What the sort?

This block prints out the first five projections of a sorted query. What "sort" argument fills the blank?

docs = list(db.laureates.find(
    {"born": {"$gte": "1900"}, "prizes.year": {"$gte": "1954"}},
    {"born": 1, "prizes.year": 1, "_id": 0},
    sort=____))
for doc in docs[:5]:
    print(doc)

{'born': '1916-08-25', 'prizes': [{'year': '1954'}]}
{'born': '1915-06-15', 'prizes': [{'year': '1954'}]}
{'born': '1901-02-28', 'prizes': [{'year': '1954'}, {'year': '1962'}]}
{'born': '1913-07-12', 'prizes': [{'year': '1955'}]}
{'born': '1911-01-26', 'prizes': [{'year': '1955'}]}