input: Write a python function to extract users' ages from a dictionary.
  assert extract_ages(users) == [28, 34, 40]
  assert extract_ages({"Alice": {"age": 25, "location": "Paris"}, "Bob": {"age": 30, "location": "Rome"}}) == [25, 30]
  assert extract_ages({"Tom": {"age": 50, "location": "Sydney"}}) == [50]
output: def extract_ages(users):
      return [info['age'] for info in users.values()]