protected double getAlpha(int an) {
		double alpha = 1;
		if (an % 3 == 0) {
			alpha = 5;
		} else if (an % 3 == 1) {
			alpha = 2;
		}
		for (int i = 0; i < an / 3 + 1; i++) {
			alpha /= 10;
		}
		return alpha;
	}