:  

   

         

              
            
.

   -    

         :   
               
.      

           
            
             
.   

       :     
              
             
. 

              
            
.

          
             
           /    
      .       
 .         
     M/GM          
              
            
               
               
.  

              
   .         
                
              
           
           
              
.    

  (  )         
.  /      