A circle is divided into $n$ equal arcs by $n$ points. Assume that, no matter how we color the $n$ points in two colors, there always exists an axis of symmetry of the set of points such that any two of the $n$ points which are symmetric with respect to that axis have the same color. Find all possible values of $n$.
Problem
Source: 1998 Estonia National Olympiad Final Round grade 11 p5
Tags: circles, points, Coloring, combinatorics, combinatorial geometry