    x x x   x x x   x x x   x
                             
                  x x       x
                             
  x               x         x
                             
          x       x       x  
                             
        x x       x   x     x
                             
  x         x x   x x     x x
                             
x x     x   x     x x x      
                             
          x   x   x x     x  
