The best establishments for higher education(I'm interested in only mathematics or/and physics) in France are not the universities but ''Les grandes écoles'',like l'Ecole Normale Supérieure (ENS for short),and l'Ecole Polytechnique. They produce a lot of great mathematicians,and have a very competitive and selective selection process. My questions are : -What the level of education do they offer ? -What do they generally assume you already know (how much math or physics?)? -How hard is it to get there?