 ;
 , ;
 _, _;

 ()
	 = ("");


 () 
	 .()>0 
		 = .(1); 
		.(1);
		 _ = 1 
			(.());
		;
		//      
		.(_);
	;
	=1;


 (, ) 
	_=?(()="", , (""));
	_=;
	_.();
	=0;
	();


 () 
	 _;


 () 
	 =1   1; ;
	 .()=0   0; ;
	();
	 ;


 () 
	.();


 (, ) 
	 = ();
	.();
	();


 () 
	 .();


