How many un vetos?

The term "un veto" is not clear in this context. If you're referring to the number of vetoes in a specific situation, such as U.N. Security Council vetoes, there are five permanent members (the U.S., U.K., France, Russia, and China) that can veto resolutions. Each of these members has the power to block any substantive resolution. If you meant something else by "un vetos," please provide more context for a more accurate response.