/* testing null references: 
assigning null to an int or a boolean results in an error
write(null) results in a parser failure
 */
class Main {
    void main() {
    	int a;
    	boolean b;
    	Object c;
    	
    	a = null;
    	b = null;
    	c = null;
    	
    	write(a);
    	writeln();
    	//write(null)

    }
}