#include "highway.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define pb push_back
#define ff first
#define ss second
void find_pair(int n, vector<int> U, vector<int> V, int A, int B){
int m = (int) U.size();
vector<pii> g[n + 1];
for (int i = 0; i < m; i++){
U[i]++; V[i]++;
g[U[i]].pb({V[i], i});
g[V[i]].pb({U[i], i});
}
vector<int> w(m);
ll nl = ask(w);
auto check1 = [&](int x){
fill(w.begin(), w.end(), 0);
for (int i = x + 1; i < m; i++) w[i] = 1;
return (ask(w) == nl);
};
int l = 0, r = m - 1;
while (l + 1 < r){
int k = (l + r) / 2;
if (check1(k)){
r = k;
}
else {
l = k + 1;
}
}
if (check1(l)) r = l;
int x = r;
vector<bool> used(n + 1);
vector<int> ed = {x};
queue<int> q({V[x], U[x]});
used[V[x]] = used[U[x]] = 1;
while (!q.empty()){
int f = q.front(); q.pop();
for (auto [i, j]: g[f]){
if (used[i]) continue;
used[i] = 1;
q.push(i);
ed.pb(j);
}
}
auto cl = [&](){
fill(w.begin(), w.end(), 1);
for (int i: ed) w[i] = 0;
};
cl();
vector<pii> t[n + 1];
for (int i: ed){
t[U[i]].pb({V[i], i});
t[V[i]].pb({U[i], i});
}
vector<int> d(n + 1), p(n + 1), pe(n + 1);
function<void(int, int, vector<int>&, vector<int>&)> dfs = [&](int v, int pr, vector<int>& E, vector<int>& q){
q.pb(v);
p[v] = pr;
for (auto [i, j]: t[v]){
if (i == pr || j == x) continue;
d[i] = d[v] + 1;
pe[i] = j;
E.pb(j);
dfs(i, v, E, q);
}
};
vector<int> d1, d2, t1, t2;
dfs(U[x], 0, d1, t1);
dfs(V[x], 0, d2, t2);
int dist = (int) (nl / A);
auto cmp = [&](int x, int y){
return (d[x] < d[y]);
};
ll AA = 1LL * dist * A;
auto solve = [&](int v, vector<int>& x2, vector<int> vv){
auto check = [&](int k){
fill(w.begin(), w.end(), 1);
for (int i: x2) w[i] = 0;
w[x] = 0;
for (int i = 1; i <= k; i++){
w[pe[vv[i]]] = 0;
}
return (ask(w) == AA);
};
int l = 0, r = (int) vv.size() - 1;
while (l + 1 < r){
int k = (l + r) / 2;
if (check(k)){
r = k;
}
else {
l = k + 1;
}
}
if (check(l)) r = l;
return (vv[r] - 1);
};
answer(solve(U[x], d2, t1), solve(V[x], d1, t2));
}
