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Bogdan and Monica playing weird games...

Source: Kyiv City MO 2022 Round 2, Problem 8.2, 11.1

January 30, 2022
combinatoricsgamegeometry

Problem Statement

Monica and Bogdan are playing a game, depending on given integers n,kn, k. First, Monica writes some kk positive numbers. Bogdan wins, if he is able to find nn points on the plane with the following property: for any number mm written by Monica, there are some two points chosen by Bogdan with distance exactly mm between them. Otherwise, Monica wins.
Determine who has a winning strategy depending on n,kn, k.
(Proposed by Fedir Yudin)