#include <bits/stdc++.h>
#include "Annalib.h"

const int N = 1e5 + 10;

std::vector <int> G[N];

void dfs(int x, int fath, bool col){
	Flag(x, col);
	for(auto y : G[x]) if(y != fath) dfs(y, fath, col ^ (y > x));
}

void Anna(int _, int n, int T, int u[], int v[]){
	for(int i = 0; i < n - 1; ++i) G[u[i]].push_back(v[i]), G[v[i]].push_back(u[i]);
	dfs(T, 0, 0);
}

#include <bits/stdc++.h>
#include "Brunolib.h"

const int N = 1e5 + 10;

void Bruno(int _, int S, int sf, int cnt, int adj[], int fl[]){
	for(int i = 0; i < cnt; ++i) if((fl[i] == sf) == (S < adj[i])){
		Answer(adj[i]);
		return void();
	}
	Answer(S);
}