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

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發送短信 : On color fixing groups associated with colored symmetrical tilings