public PointGame getUpNeighbor() {
		int x0 = x;
		int y0 = y;
		while (y0 > MINY) {
			// check if x=3 and y=4, we cannot go down.
			if (x0==3 && y0==4)
				break;
			y0--;
			if (Board.validPoints.contains(new PointGame(x0,y0))) {
				return new PointGame(x0,y0);
			}
		}
		return null;
	}