two numbers in each vertice of a convex $100$-gon
Source: All-Russian 2007
May 4, 2007
inductionalgebrapolynomialfunctioncombinatorics proposedcombinatorics
Problem Statement
Two numbers are written on each vertex of a convex -gon. Prove that it is possible to remove a number from each vertex so that the remaining numbers on any two adjacent vertices are different.
F. Petrov