Iberoamerican Olympiad 2013 - Problem 5
Source: http://oim2013.opm.org.pa/pdfs/examen_pt.pdf
August 13, 2014
number theory proposednumber theory
Problem Statement
Let and be two sets such that is the set of the positive integers, and is the empty set. It is known that if two positive integers have a prime larger than as their difference, then one of them is in and the other is in . Find all the possibilities for the sets and .