xxxxxxx  xxxxxx  xxxxxx  xxxxxxx
x          xxx                 x
x     s    xxx                 x
x          xxx         s       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            xxxxx             x
             xxxxx              
                 x              
x                x             x
x                x             x
x                x             x
x     e          x       e     x
x                x             x
x                x             x
                 x              
                 x              
x                x             x
x                x             x
x                x             x
x          s     xxxxxx        x
x                xxxxxx        x
x                xxxxxx        x
xxxxxxx  xxxxxx  xxxxxx  xxxxxxx