               .

             ,
         .
        :

-----------------------------------
| ...........           |
| ............           |
| .(,,-)....           |
| .(,,-).           |
|  (,,)           |
|/ (+/-)...           |
-----------------------------------

F1  F2/+   F3   F4   F10 

             
.     ,   
,       ,  
   .      
    . 
	      . 
     ""   ,  
  .       .
               ,   
  F3      
,   .    
    Enter     
      .  
          
.
              "-",  
 ,        .
               
           
  .      
  ,      
    F4    .
             F2  + .  
  :

----------------------------------------------
|  .                        |
|    .|
|.                                      |
----------------------------------------------
              .
 :

-------------------------------------
|  .   |
|   .|
| .                     |
|.                             |
-------------------------------------

	     
         
c.       , 
       .
             ,   
   .
