void OnGUI()
    {
        GUI.Box(new Rect(15, 15, 150, 70), "");
        GUI.Label(new Rect(25, 25, 130, 30), output);        
        if (num == 0 || output=="遊戲結束")
        {
            if (GUI.Button(new Rect(25, 45, 130, 30), "try again(Y/N)?"))
            {
                UnityEngine.SceneManagement.SceneManager.LoadScene(0);
            }
        }
    }