The International Mathematical Olympiad is the World Championship Mathematics Contest for second level students. Each country is invited to send a team of up to six students to compete in this contest. The competition itself involves tackling very difficult mathematical problems which require a great deal of ingenuity to solve. Participation alone in this competition is regarded as very prestigious. Indeed, many of the world's leading mathematicians are past participants of the IMO.
The official homepage of the IMO contains problem listings and statistics on the participation of all countries.
The 61st International Mathematical Olympiad will take place in St. Petersburg, Russian Federation, from 8 - 18 July 2020.