private static int getIntersectionNum(List<Integer> leftWindow, List<Integer> rightWindow){
		int intersectionNum = 0;
		
		Map<Integer, Integer> wireMap = new HashMap<Integer, Integer>();
		
		for (int i = 0; i < leftWindow.size(); i++){
			wireMap.put(leftWindow.get(i), rightWindow.get(i));
		}
		
		for (Integer key : wireMap.keySet()){
			for (int i = 0; i < leftWindow.size(); i++){
				if (key == leftWindow.get(i)){
					continue;
				}
				
				if (key > leftWindow.get(i) && wireMap.get(key) < rightWindow.get(i)){
					intersectionNum++;
				}
				
				if (key < leftWindow.get(i) && wireMap.get(key) > rightWindow.get(i)){
					intersectionNum++;
				}
			}
		}
		
		return intersectionNum/2;
	}