import java.awt.*;

class SCL {
  // screen coordinate list
  int x,y; // coordinate pair
  SCL link; // link to next one
 
  SCL() { link = null;}
  
  SCL(SCL link, int x, int y) {
    this.x = x; this.y = y; this.link = link;
  } 
  
  
} // SCL