30 June 2020

• 21:3021:30, 30 June 2020 diff hist +115 Olympiad books →Geometry

21 June 2020

• 20:2320:23, 21 June 2020 diff hist +674 N 2020 USOJMO Problems/Problem 1 Created page with "Let <math>n \geq 2</math> be an integer. Carl has <math>n</math> books arranged on a bookshelf. Each book has a height and a width. No two books have the same height, and no t..."