發送短信 : Category hierarchy maintenance : a data-driven approach

  _____    __   __    _  _     _____     _____   
 |__  //   \ \\/ //  | \| ||  |  ___||  /  ___|| 
   / //     \ ` //   |  ' ||  | ||__   | // __   
  / //__     | ||    | .  ||  | ||__   | \\_\ || 
 /_____||    |_||    |_|\_||  |_____||  \____//  
 `-----`     `-`'    `-` -`   `-----`    `---`