public class X {
public void foo(X x){
System.out.println("X.X");
}
public void foo(Y x){
System.out.println("X.Y");
}
}
public class Y extends X{
public void foo(Y x){
System.out.println("Y.Y");
}
public void foo(X x){
System.out.println("Y.X");
}
}
public class...
