       7 
                              
                                                
    
                                         
                                                                  
                                                             
                                                                                                                        
      7 
                                                                                                                
1     
                                                                       
2     
                                                    
3    
                                   
4   
                                         
5      
                                                                   
6     
                                                              
7     
                                                          

                                           
             