IMO Shortlist 1999 problem C6
Dodao/la: arhiva2. travnja 2012.
Suppose that every integer has been given one of the colours red, blue, green or yellow. Let
be odd integers so that
. Show that there are two integers of the same colour whose difference has one of the following values:
Izvor: Međunarodna matematička olimpijada, shortlist 1999