用户要求的格式请使用JSON格式: dict表示城市(city)的经纬度(x,y)，每对经纬度代表一个城市。
*{"Beijing": (39.9042, 116.4074), "Shanghai": (31.2304, 121.4737), "Guangzhou": (23.1291, 113.2644)}*
user
{
  "Beijing": {"x": 39.9042, "y": 116.4074},
  "Shanghai": {"x": 31.2304, "y": 121.4737},
  "Guangzhou": {"x": 23.1291, "y": 113.2644}
}
assistant