First Bad Versioin

	public int findFirstBadVersion(int n) {
		int lb = 0, ub = n + 1;
		while (lb + 1 < ub) {
			int mid = lb + (ub - lb) / 2;
			if (VersionControl.isBadVersion(mid)) {
				ub = mid;
			} else {
				lb = mid;
			}
		} 
		return lb + 1;
		}
	}