public List<Integer> search() throws InterruptedException {
		List<Integer> result = new ArrayList<>();
		Searcher[] searchers = new Searcher[threads];
		int quantityOfNumbers = upperBound - lowerBound;
		if (threads > quantityOfNumbers) // optimization , don't need extra threads
			threads = quantityOfNumbers;

		int delimiter = quantityOfNumbers / threads;
		int rest = quantityOfNumbers % threads + 1; //
		searchers[0] = new Searcher(lowerBound, lowerBound + delimiter - 1);
		for (int i = 1; i < threads; i++) {
			int extra = (rest > 0) ? 1 : 0;
			rest--;
			searchers[i] = new Searcher(searchers[i - 1].getUpperBound() + 1,
					searchers[i - 1].getUpperBound() + delimiter + extra);
		}
		/*
		for (int i = 0; i < threads; i++) {
			System.out.println(i + " ---> " + searchers[i].getRanger());
		}
*/
		for (int i = 0; i < threads; i++) {
			searchers[i].start();
		}
		for (int i = 0; i < threads; i++) {
			searchers[i].join();
		}

		for (int i = 0; i < threads; i++) {
			result.addAll(searchers[i].getResult());
		}
		return result;
	}