IEnumerator QuitGame()
    {
        fadingScreen.gameObject.SetActive(true);
        fadeOut = true;
        StartCoroutine(GM.AudioFadeOut(Bgm, fadingTime));
        yield return(new WaitForSeconds(fadingTime));

        fadeOut = false;
        Application.Quit();
    }
 public IEnumerator ChangeToMonsterBgm()
 {
     StartCoroutine(GM.AudioFadeOut(Bgm, fadingTime));
     StartCoroutine(GM.AudioFadeIn(monsterBgm, fadingTime));
     yield return(new WaitForSeconds(fadingTime));
 }