+------------+        
       |            |        
       |            |        
       |            |        
       +------|-----+        
              |              
              |              
              |              
              |              
              |              
       +------|-----+        
       |            |        
       |            |        
       |            |        
       +------------+        
              |              
              |              
              |              
              |              
              |              
              |              
         +----|----+         
         |         |         
         |         |         
         |         |         
         +----|----+         
              |              
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              |              
              |              
              |              
      +-------|------+       
      |              |       
      |              |       
      |              |       
      +-------+------+       
              |              
              |              
              |              
              |              
              |              
              |              
        +-----|------+       
        |            |       
        |            |       
        |            |       
        +-----|------+       
              |              
              |              
              |              
              |              
              |              
+-------------|-------------+
|                           |
|                           |
|                           |
+-------------+-------------+
              |              
              |              
              |              
              |              
              |              
              |              
      +-------|------+       
      |              |       
      |              |       
      |              |       
      +-------|------+       
              |              
              |              
              |              
              |              
              |              
        +-----|------+       
        |            |       
        |            |       
        |            |       
        +------------+