Points and colored segments
Source: All-Russian 2021/9.1
April 19, 2021
combinatoricsAll Russian OlympiadRussia
Problem Statement
On a circle there're marked points, each colored in one of colors. It's known that among any pairwise intersecting segments, endpoints of which are distinct marked points, there're at least segments, each of which has its endpoints colored in different colors. Determine the smallest possible value of for which it's possible.