What's the Name of That Book??? discussion

Hi! I’m looking for a book I read in 2013 or so. I believe it was set in the future and the city where the majority of the population lived was under attack. All of the teenagers were sent to this school out in the middle of no where that was run by a few very suspicious, strong women. The teens were taught survivalist skills and sent through a bunch of challenges. One of these challenges I can specifically recall was them being put in groups and sent out into the woods to survive for three days or so. (SPOILERS) in the end two of the main characters end up sneaking around because their little group has planned on escaping the school, and they overhear the headmistress talking about using the teenagers in the war against their own home and using them for ransom from their parents. That’s just about all I can recall about the plot. I really don’t remember much about the appearance of the book, I think there was a couple of kids running on the cover? Please please help me find this book!! Thank you

Behind the Gates by Eva Gray probably?

Ayshe wrote: "Behind the Gates by Eva Gray probably?"
I think that might be it, thank you so much!

Jade, how confident are you? We can put this in Possibly Solved until you find out. Or if you're 99% sure, we can just move it to Solved.

Lobstergirl wrote: "Jade, how confident are you? We can put this in Possibly Solved until you find out. Or if you're 99% sure, we can just move it to Solved."
That is definitely the book, I read the first couple of pages of an online copy to be sure.