story identification - A book about teenagers isolated in a school with robot teachers and no adults

I have been looking for this book but I'm clueless about the title or the author, and the google searches with the plot details I remember have been useless so far. But perhaps somebody here knows the book I'm talking about, so here it goes.

I read it after year 2000 and no later than 2008, but it could have been published decades earlier for all I know.

The plot was about a group of teenagers that lived in a school, in a kind of dystopian future. They had never been outside of the school building. They had no contact with the world outside, nor any idea of what was outside the school. There were no adults in the school and the teachers were robots. I remember something about recorded tape lessons. Perhaps the "teachers" were recorded video tapes, or the robots were basically playing lessons recorded in video tapes.

Somehow, at the end of the book, the robot-teacher breaks and the teenagers get out of the school to discover the world outside. And there is where the story ends, as far as I remember, the book never tells what do the teenagers actually find outside the school.

I think that the book was narrated in first person from the perspective of a boy, but I'm not sure.

Maybe there were some clues in the story about something very bad having happened long ago and the teenagers having been put in that school to save them from a disaster in the world outside and the rest of the civilization being gone after that disaster.

The book wasn't very long, probably not more than 200 pages, perhaps less. And I think it was addressed to a teenager audience.

This is all I can remember about that book. I know the details are very vague, but if by chance anybody knows the book I'm talking about, I'll be very grateful to be able to find it again.

Thanks!

Answer

Sounds a bit like E.G. Von Wald HEMEAC, except that at the end it's people from outside who come in rather than vice versa.

One of the outsiders asks "What do we do with them? They're nothing but living robots", and Hemeac feels a warm glow of pride at the compliment.

Does that ring a bell?