What do I need to watch for avengers doomsday?

I know this has been asked alot but I haven't found a list that only contains characters that are actually appearing or/and are relevant. Most lists I've found are extremely stopped down or bloated such as some saying that I need to watch daredevil although he's not even appearing in doomsday. And to the list if only a single movie is necessary but it's in a franchise is also like to watch the franchise.