▒.      ...         
                ▒.      ..▒         
                ▒..    ▒..▒         
               ▒▒..    ...▒         
              ▒▒....▒▒▒...▒         
              ▒.....▒.....▒▒        
              .............▒▒       
              .......<......▒▒      
              ........@.......      
              ....▒▒▒▒........      
              ▒..    ▒▒▒......      
              ▒         ▒▒....      
                           ▒S.      
                             .      
                          ▒▒....    
                          ▒.....    
                          ▒....▒▒   
                       ▒▒▒......▒   
                       .........▒   
                        .... ...▒   
                         ▒..▒▒@h▒▒  
                         ▒...▒<S.▒  
                          ▒..▒▒e.▒▒▒
                          ▒..e.....▒
                          ▒....▒▒▒▒▒
                         ▒....▒▒    
                        ▒....▒▒     
                       ▒e....       
                      ▒......       
                      .......       
                      .......       
                      .......       
                                    
∩