labelling vertices of 1997-gon
Source: French MO 1997 P1
April 10, 2021
combinatorics
Problem Statement
Each vertex of a regular -gon is labeled with an integer, so that the sum of the integers is . We write down the sums of the first integers read counterclockwise, starting from some vertex . Can we always choose the starting vertex so that all these sums are positive? If yes, how many possible choices are there?