    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   x     x
