input: Write a python function to parse a JSON string and extract the values of keys "name", "age", and "city".
  assert parse_json('{"name":"John", "age":30, "city":"New York"}') == ("John", 30, "New York")
  assert parse_json('{"name":"Alice", "age":25, "city":"Los Angeles"}') == ("Alice", 25, "Los Angeles")
  assert parse_json('{"name":"Bob", "age":22, "city":"Chicago"}') == ("Bob", 22, "Chicago")
output: import json
  
  def parse_json(json_str):
      data = json.loads(json_str)
      return data["name"], data["age"], data["city"]