#include "highway.h"
#include <bits/stdc++.h>
#define pii pair<int, int>
#define szof(s) (int)s.size()
#define fr first
#define sc second
using namespace std;
const int N = 90004;
vector <pii> g[N];
int x[N], y[N];
int n, m, a, b;
int S, T;
vector <int> w;
void create(vector <int> &path) {
for (int i = 0; i < m; i++) {
w[i] = 0;
}
for (int edge : path) {
w[edge] = 1;
}
}
void dfs(int v, int par, vector <int> &path) {
if (v != 0) {
create(path);
int dist = ask(w);
if (dist == szof(path) * b) {
S = 0, T = v;
}
}
for (pii to : g[v]) {
if (to.sc != par) {
path.push_back(to.fr);
dfs(to.sc, v, path);
path.pop_back();
}
}
}
void find_pair(int NN, vector<int> U, vector<int> V, int A, int B) {
n = NN;
m = U.size();
a = A;
b = B;
w.resize(m);
for (int i = 0; i < m; i++) {
x[i] = U[i];
y[i] = V[i];
g[x[i]].push_back({i, y[i]});
g[y[i]].push_back({i, x[i]});
}
vector <int> path = {};
dfs(0, -1, path);
answer(S, T);
}
