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

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發送短信 : On semigroups of endomorphisms of a chain with restricted range