public static double divisionPositivesByNegatives(int[] mass) {
		if (mass.length == 0)
			System.err.println("Cann`t make a calculation: "
					+ "division positive elements of massiv by negative.");
		double positives = 0, negatives = 0;
		int i = 0;
		while (mass.length < i) {
			if (mass[i] < 0)
				negatives += mass[i];
			else 
				positives += mass[i];
			i++;
		}
		
		return (positives != 0 & negatives != 0) ? (positives / negatives) : 0;
	}