words
Source: Bulgarian Math Olympiad MO 2004, problem 4
May 17, 2004
invariantinductionfunctiongeometrygeometric transformationgroup theorycombinatorics proposed
Problem Statement
In a word formed with the letters we can change some blocks: in and back, in and backwards. If the initial word is where appears 2003 times can we reach the word , where appears 2003 times.