#include "highway.h"
#include <bits/stdc++.h>
int n, m;
std::vector <std::vector <int>> g;
long long dist;
void find_pair(int _n, std::vector <int> _u, std::vector <int> _v, int a, int b) {
n = _n;
m = _u.size();
g.resize(n);
for (int i = 0; i < m; i++) {
g[_u[i]].push_back(i);
g[_v[i]].push_back(i);
}
dist = ask(std::vector <int> (m, 0)) / a;
int root[2] = { -1, -1 };
int sec = -1;
{
std::vector <int> cur(m, 1);
int left = m;
while (left > 1) {
auto cop = cur;
int mid = left >> 1;
for (int i = 0; i < m && left > mid; i++) {
if (cur[i]) {
left--;
cur[i] = 0;
}
}
long long val = ask(cur);
if (val > dist * a) {
left = 0;
for (int x : cur) {
left += x;
}
} else {
left = 0;
for (int i = 0; i < m; i++) {
if (cur[i] && cop[i]) {
cop[i] = 0;
}
left += cop[i];
}
cur = cop;
}
}
assert(left == 1);
for (int i = 0; i < m; i++) {
if (cur[i]) {
sec = i;
root[0] = _u[i];
root[1] = _v[i];
break;
}
}
}
assert(root[0] != -1 && root[1] != -1);
assert(sec != -1);
std::vector <int> nod[2];
std::vector <int> par(n, -1);
{
std::queue <std::pair <int, std::pair <int, int>>> q;
q.push({ root[0], { sec, root[0] } });
q.push({ root[1], { sec, root[1] } });
std::vector <bool> vis(n, false);
while (q.size()) {
int rt = q.front().first;
int pa = q.front().second.first;
int v = q.front().second.second;
q.pop();
if (vis[v]) {
continue;
}
vis[v] = true;
par[v] = pa;
nod[rt == root[0] ? 0 : 1].push_back(v);
for (int x : g[v]) {
int to = v ^ _u[x] ^ _v[x];
q.push({ rt, { x, to } });
}
}
}
int ans[2];
for (int i = 0; i <= 1; i++) {
int l = 0, r = (int) nod[i].size() - 1, best = nod[i][0];
while (l <= r) {
int mid = (l + r) >> 1;
std::vector <int> cur(m, 1);
for (int x : nod[i ^ 1]) {
cur[par[x]] = 0;
}
for (int j = 0; j <= mid; j++) {
cur[par[nod[i][j]]] = 0;
}
long long val = ask(cur);
if (val > dist * a) {
best = nod[i][mid + 1];
l = mid + 1;
} else {
r = mid - 1;
}
}
ans[i] = best;
}
answer(ans[0], ans[1]);
}
