public static XY[] getXYfromInput(String input) {
		if (input.length() != 4) {
			return null;
		}
		char[] inputChars = input.toCharArray();
		if (!(inputChars[0] == inputChars[2] && inputChars[1] == inputChars[3])) {
			XY from = getNewXY(inputChars[0], inputChars[1]);
			XY to = getNewXY(inputChars[2], inputChars[3]);
			if (from == null || to == null) {
				return null;
			} else {
				return new XY[] { from, to };
			}
		}
		return null;
	}