void SetExtraArea()
    {
        MissionData.AreaSetData areaSetData;
        if (id % nextBossArea == 0 && !isBossOn)
        {
            areaSetData = GetBossArea();
        }
        else
        {
            areaSetData = GetArea();
        }

        print("new XTRA: " + areaSetData.areas.Count);
        missions.CreateCurrentArea(areaSetData.areas[UnityEngine.Random.Range(0, areaSetData.areas.Count)], true);
        id++;
    }