ex9

https://software.thaiware.com/3466-%E0%B9%82%E0%B8%9B%E0%B8%A3%E0%B9%81%E0%B8%81%E0%B8%A3%E0%B8%A1_%E0%B8%AB%E0%B8%B2%E0%B8%87%E0%B8%B2%E0%B8%99%E0%B8%94%E0%B8%B4%E0%B8%99_CF.html