private static int isTwoPairs(ArrayList<Card> list) {
		assert(list.size() == EFFECTIVE_CARD_NUM);
		
		if (containSet(list) >= 0 || isKingKong(list) >= 0){
			return -1;
		}
		
		if (list.get(0).getPoint() == list.get(1).getPoint() && 
				list.get(2).getPoint() == list.get(3).getPoint()) {
			return list.get(2).getPoint();
		}
		
		if (list.get(0).getPoint() == list.get(1).getPoint() && 
				list.get(3).getPoint() == list.get(4).getPoint()) {
			return list.get(3).getPoint();
		}
		
		if (list.get(1).getPoint() == list.get(2).getPoint() && 
				list.get(3).getPoint() == list.get(4).getPoint()) {
			return list.get(3).getPoint();
		}
		
		return -1;
	}