Factoring Game
Source: 2006 Korea National Olympiad #2
March 18, 2018
primesCombinatorial gamescombinatorics
Problem Statement
Alice and Bob are playing "factoring game." On the paper, is written and each person picks one number from the paper(call it ) and erase and writes integer such that and Alice goes first and the person who can no longer make this factoring loses. If two people use optimal strategy, prove that Alice always win.