Does anyone know ICPC 2024 WF teams from Asia Pacific Region? How is it even calculated in the first place?

How to solve this adhoc task?

You are given an undirected graph with $$$N$$$ vertexes and $$$M$$$ edges. Each vertex $$$i$$$ has a value, $$$a[i]$$$.

Is is possible to make all vertexes have the same value, using the following operation multiple times (or not use it at all):
- If there is a vertex $$$u$$$, such that vertexes $$$v$$$ and $$$w$$$ are directly connected to it, then change $$$a[v]$$$, $$$a[w]$$$ to $$$a[v] + k$$$ and $$$a[w] + k$$$ respectively, where $$$k$$$ is any integer.

If it is possible, print "YES", else "NO".

$$$N$$$ <= 100000, $$$M$$$ <= 200000

Link: https://www.acmicpc.net/problem/30187

I have been thinking in direction that if it is not a bipartite graph, then answer is YES. No idea is that even right or not.

Is there any kind of editorial for Balkan Olympiad in Informatics 2018?

Is there editorial for apio 2013 toll?