    2021  5  15      
            2021   5   19      
             
        
                         
   
1                             1500        
2                                  
3                
                          
                      
   
 1      
                  
 2      
           
   
1    9                                                1500                            
2           
     1                      
     2                                                  
3         
4                       
5            
    
                             
     
       9                                  
    
   
                                                            
  
                                                                                                                                                                 
                                                                                 
                                                                             