But anyway, I could, we could do a whole series of videos on viruses, but the flu is a virus and what happens every year is that you have a certain type of virus a certain type of virus and they have some variation and I'll just make the variation by how many dots they have. how many dots they have and they, in fact, - let's say it is a human flu, they infect humans - and slowly our immune systems, which we could make a whole set of videos on as well, start to recognize the virus and are able to attack them before they can do a lot of damage.