请列出世界前五位的城市天际线，并以json格式输出
user
```json
{
  "top_city_skylines": [
    {
      "city": "香港",
      "country": "中国"
    },
    {
      "city": "纽约",
      "country": "美国"
    },
    {
      "city": "芝加哥",
      "country": "美国"
    },
    {
      "city": "迪拜",
      "country": "阿联酋"
    },
    {
      "city": "上海",
      "country": "中国"
    }
  ]
}
```
assistant