The International Mathematical Olympiad (IMO) is the largest, oldest and most prestigious scientific Olympiad for high school students. The history of IMO dates back to 1959, when the first edition was held in Romania with seven countries participating: Romania, Hungary, Bulgaria, Poland, Czechoslovakia, East Germany, and USSR. Since then, the event has been held every year (except 1980) in a different country. Currently, more than 100 countries from 5 continents participate. Each country can send a team of up to six secondary students or individuals who have not entered University or the equivalent, as of the date of celebration of the Olympiad, plus one team leader, one deputy leader, and observers if desired.
During the competition, contestants have to solve, individually, two contest papers on two consecutive days, with three problems each day. Each problem is worth seven points. Gold, silver, and bronze medals are awarded in the ratio of 1:2:3 according to the overall results — half of the contestants receive a medal. In order to encourage as many students as possible to solve complete problems, certificates of honorable mention are awarded to students (not receiving a medal) who obtained 7 points for at least one problem.