xxxxxxx  xxxxxx  xxxxxx  xxxxxxx
x                              x
x               s              x
x                              x
x   xxxxxxxxxxxxxxxxxxxxxxxx   x
x   x2222222222222222222222x   x
x   x2         m          2x   x
    x2                    2x    
    x2                    2x    
x   x2                    2x   x
x   x2                    2x   x
x   x2                e   2x   x
x   x2                    2x   x
x   x2                    2x   x
x   x2                    2x   x
               s                
                                
x   x2                    2x   x
x   x2                    2x   x
x   x2                    2x   x
x   x2   e                2x   x
x   x2                    2x   x
x   x2                    2x   x
    x2                    2x    
    x2                    2x    
x   x2         c          2x   x
x   x2222222222222222222222x   x
x   xxxxxxxxxxxxxxxxxxxxxxxx   x
x                              x
x              s               x
x                              x
xxxxxxx  xxxxxx  xxxxxx  xxxxxxx