void Update()
    {
        if (lastFloor.x < transform.position.x + 11)
        {
            NextFloor();
        }
        foreach (var transf in floors)
        {
            if (transf.transform.position.x < transform.position.x - 20)
            {
                floors.Remove(transf.gameObject);
                Destroy(transf);
            }
        }
    }