My Favorite Math Competition Problem, Part 1.

In 2024, an ORMC student-turned-volunteer-instructor, Tiger (Qiao) Zhang, won a gold medal at the International Math Olympiad (IMO). ORMC is short for UCLA Olga Radko Endowed Math Circle, a free Sunday math school for gifted children run by UCLA Department of Mathematics. To honor Tiger's achievement, we had a mini-conference, called My Favorite Math Competition Problem. Four speakers, all IMO medalists, presented their favorite problems, including solutions and mathematical background. This is part 1 of the presentation. The speaker is Nikita Gladkov, an IMO 2015 silver medalist and a grad student at the department as of 2024.