      
     
      
                   
                                                                                                                                                                        
                                         
            
                                                                                             
                                                                                                                                                                                                                                                                                                                     
            
                                                                                                                                                                                                                                                                                                                          
            
                                                                                                                                                                                                                                                                                                                                                             
                                
                             1                       2                         3                                                                                          
                                                                                                                                                                                                       