请说出A类中System.out.println的输出结果。
class B{
int x = 100,y=200;
public void setX(int x){
x=x;
}
public void setY(int y){
this.y=y;
}
public int getXYSum(){
return x+y;
}
}
public class A {
public static void main(String args[ ]){
B b =new B();
b.setX(-100);
b.setY(-200);
System.out.println("sum="+b.getXYSum());
}
} 
