import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.stage.Stage;

public class MaxStage extends Application {
    public void start(Stage primaryStage) {
        primaryStage.setScene(new Scene(new Group(), 20000, 20000));
        primaryStage.sizeToScene();
        primaryStage.show();
    }
    public static void main(String[] args) {
        Application.launch(args);
    }

}