發送短信 : Appointment systems under service level constraints

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