Skip to content / Đến nội dung
ThichHocToan.com

MathNet 2008-part-04 — 165 problems (EN–VI) Question 30

Math Olympiad Vault · MathNet 2008-part-04 — 165 problems (EN–VI)

Question 30

Two players have a pile of identical tokens, from which they alternately take one token each and place it on any empty cell of a square board of size $2008 \times 2008$. The winner is the player who first places a token so that, together with three other tokens, it forms the vertices of an isosceles trapezoid that is not a rectangle and whose bases are parallel to one of the edges of the board. Which player has a winning strategy: the one who started the game, or the other player?