Hardest problem in IMO

Nairi Sedrakyan is the author of one of the hardest problems ever proposed in the history of the International Mathematical Olympiad (IMO), 5th problem of 37th IMO. This problem is considered to be one of the hardest problems ever because none of the members of the strongest teams, i.e. the National Olympic Teams of the USA, Russia or China succeeded to solve it correctly. Moreover, the National Olympic Team of China obtained a cumulative result equal to 0 points and was ranked 6th in the final ranking of the countries instead of the usual 1st or 2nd place. The British 2014 film X+Y, released in the USA as A Brilliant Young Mind, inspired by, Beautiful Young Minds focuses on a English mathematical genius chosen to represent the United Kingdom at the IMO. In the film this problem is stated to be the hardest problem ever proposed in the history of IMO (minutes 9:40-10:30). Other outstanding results of the author include having 4 problems in the shortlist of the 27 problems selected worldwide of the 40th IMO in Romania and having 5 medals winner students in 41st IMO in South Korea. As all winning students were from the same school, where Nairi Sedrakyan was teaching mathematics, the government of the Republic of Armenia awarded him the title of the best teacher of the Republic of Armenia and he received a special gift from the Prime Minister. The students of Nairi Sedrakyan have obtained 20 medals (1 gold medal, 4 silver medals, 15 bronze medals) in IMO, providing more than half of the medals that the Republic of Armenia received in the history of its participation in IMO. So far it is the single gold medal of the Republic of Armenia in IMO. In particular, one of the medals in IMO was received by his son Hayk Sedrakyan (later on he became a Professor of mathematics in Paris and a professional math Olympiad Coach in the greater Boston area, Massachusetts, USA, having received his PhD in mathematics from the Pierre and Marie Curie University (Sorbonne University) in Paris, France).