It's one of the most closed and repressive societies on earth. Its ruthless young leader Kim Jong-un has threatened nuclear war against America and recently executed his own uncle. Yet in the heart of North Korea's absolute dictatorship, a remarkable university - paid for by the west - is attempting to open the minds of the secretive state's future elite. Panorama has gained unprecedented access to this most unusual of academic institutions - which is educating the sons of the brutal regime. Reporter Chris Rogers lives with them on campus and asks: can the class of 2014 help to bring the hermit nation in from the cold?