發送短信 : Colorings of Hyperbolic Plane Crystallographic Patterns

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