Add Controller class.

src/Controller.java

+public class Controller {
+    public static String userName;
+}

src/Main.java

 public class Main {
 
     public static void main(String[] args) {
-        System.out.println("Hello World!");
+        new LoginFrame();
+        //new MainFrame();
+        //new SettingFrame();
+        //new OnlineModeFrame();
+        //new CreateNewGameFrame("Make");
+//        JFrame jFrame = new JFrame();
+//        jFrame.setBounds(500,500,700,400);
+//        jFrame.add(new Map());
+//        jFrame.setVisible(true);
     }
 }