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MathNet 2011 Question 90

Math Olympiad Vault · MathNet 2011

Question 90

Let $M$ be convex 2011-gon. Consider 2011 points lying inside $M$ and such that no three of all 4022 points (the vertexes of $M$ and 2011 points inside $M$) are collinear. A coloring of all points in two colors is called good if it is possible to connect some of the points by segments such that the following conditions hold:
(1) Each segment has its endpoints of one and the same color.
(2) No segments intersect in inner points.
(3) Between any two points of the same color there exists a path through the given segments.
Find the number of all good colorings.