In France, the Concours Général is the most prestigious academic competition held every year between students of "Première" (11th grade) and "Terminale" (12th and final grade) in almost all subjects taught in both general, technological and professional high schools. Exams usually take place in March, and their results are known in June or July. Students who show great ability in one field are selected to participate by their teachers and their school principal. Most of the time, no more than one student per high school is allowed to participate in the competition, which requires strong knowledge of college level topics. In the humanities and social sciences, the exams involve one or more essays and last 6 hours. In the sciences, the exams last almost as long and are problem-based.