MathDB
A and B take stones from a pile

Source: CentroAmerican 2003

November 29, 2010
combinatorics proposedcombinatorics

Problem Statement

Two players AA and BB take turns playing the following game: There is a pile of 20032003 stones. In his first turn, AA selects a divisor of 20032003 and removes this number of stones from the pile. BB then chooses a divisor of the number of remaining stones, and removes that number of stones from the new pile, and so on. The player who has to remove the last stone loses. Show that one of the two players has a winning strategy and describe the strategy.