public int compareTo(City c) {
		if (CENTER.x/25==c.CENTER.x/25)
			return CENTER.y-c.CENTER.y!=0?CENTER.y-c.CENTER.y:CENTER.x-c.CENTER.x;
		else
			return CENTER.x-c.CENTER.x!=0?CENTER.x-c.CENTER.x:CENTER.y-c.CENTER.y;
	}