static int findMissingNumber(int start, int end, List<Integer> list) {

		/*
		 * Collections.sort(list); for (int item : list) { if(start != (int)item) {
		 * return start; } start++; } return end;
		 */
		
		/*
		 * for (int i=start; i<=end; i++) { if (!list.contains(i)) { return i; } }
		 * return 0;
		 */
		 
		int sum = list.stream().reduce(Integer::sum).orElse(0);
		return (start+end)*(end-start+1)/2-sum;
		
	}