gabriel leung, the dean of medicine at the university of hong kong, told me the new developments in thea challenge. the research that we just finished 24—hours ago has now moved on. it is spreading that quickly. since we have looked at this 2a hours ago, there has been a taiwanese case and now a us case exported from wuhan and that is what worries us quite a lot. what we've done is to take the overseas exported cases and then did a backward inference to estimate the likely pool of cumulative confirmed cases in wuhan itself, and then take that number to say looking at rail patterns, road patterns and air traffic patterns domestically within mainland china, what we are likely to have already seen or observed in terms of exporting outside of the borders of wuhan, to other places nationally and what might happen given the spring festival travel season, which actually began on january the 10th and lasts a0 days. that's really what our model has been trying to do, and we need to go back and now update it because of how things have moved so quickly. as you say, the timing can't be much worse w