private static String new_first_of_sequence(Hashtable<String, Tuple<LinkedList<Integer>, Integer>> queues) {
		Iterator<String> words = queues.keySet().iterator();
		int min = Integer.MAX_VALUE;
		String min_word = "";
		while(words.hasNext()){
			String word = words.next();
			Tuple<LinkedList<Integer>, Integer> tuple = queues.get(word);
			LinkedList<Integer> queue = tuple.get_x();
			if(!queue.isEmpty()){
				int value = queue.getFirst();
				if(value < min){
					min = value;
					min_word = word;
				}
			}
		}
		return min_word;
	}