For me, it's a bit special. I attend 3 years of special school (called "Mathématiques Supérieures" and "Mathématiques Speciales"), where the only think you do is learn math, physics at a very high dose, and a few chemistry, the goal being to take (and pass) entry examinations for Engineer schools (we called it "Grandes Ecoles").
As it's quite hard, we usually take as many exam as possible, but we have to make some choices (the last about one week each, and as they are all in june... we cannot take all of them).
However, several schools are grouped together in the same exam. You make a list of the schools in order of preference, and then guy with the best score choose first.
For me, I take 5 exams, passed 3, and finally select ENAC (the French Civil Aviation University), for the Computer Science and Air Traffic engineer option.
I'm happy, because it was my first choice§. For information, they took 86 people, and there was 4,500 taking the exam.