MathDB
Giant square - Portuguese MO, Problem 3, 2009

Source:

August 29, 2010
combinatorics proposedcombinatorics

Problem Statement

Duarte wants to draw a square whose side's length is 20092009 cm and which is divided in 2009×20092009\times2009 squares whose side's length is 11 cm and whose sides are parallel to the original square's one, without taking the pencil out of the paper. Starting on one of the vertex of the giant square, what is the length of the shortest line that allows him to make this drawing?