#include <bits/stdc++.h>
#include "highway.h"
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define ALL(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
// mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng(1);
ll rngesus(ll l, ll r){return ((ull) rng()) % (r - l + 1) + l;}
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll LASTBIT(ll mask){return mask & (-mask);}
ll pop_cnt(ll mask){return __builtin_popcountll(mask);}
ll ctz(ll mask){return __builtin_ctzll(mask);}
ll clz(ll mask){return __builtin_clzll(mask);}
ll logOf(ll mask){return 63 - clz(mask);}
template <class T1, class T2>
bool minimize(T1 &a, T2 b){
if (a > b){a = b; return true;}
return false;
}
template <class T1, class T2>
bool maximize(T1 &a, T2 b){
if (a < b){a = b; return true;}
return false;
}
template <class T>
void printArr(T& a, string separator = " ", string finish = "\n", ostream& out = cout){
for(auto i: a) out << i << separator;
out << finish;
}
template <class T>
void remove_dup(vector<T> &a){
sort(ALL(a));
a.resize(unique(ALL(a)) - a.begin());
}
const int N = 1e5 + 69;
int n, m;
vector<pair<int,int>> graph[N];
vector<pair<int, int>> DAG[N];
void dfs(int u, vector<int> &topo){
for(pair<int, int> v: DAG[u]){
dfs(v.first, topo);
topo.push_back(v.second);
}
}
// struct P{
// ll i, w;
// P(){}
// P(ll _i, ll _w){i = _i, w = _w;}
// };
// struct compare{
// bool operator () (P a, P b) {return a.w > b.w;}
// };
// namespace Grader{
// int n, m;
// int s, t;
// int x, y;
// vector<int> U, V;
// int A, B;
// int o_cnt = 0;
// ll ask(vector<int> w){
// o_cnt++;
// vector<vector<P>> graph(n);
// for(int i = 0; i<w.size(); ++i){
// int u = U[i], v = V[i];
// int cur_w = A;
// if (w[i]) cur_w = B;
// graph[u].push_back(P(v, cur_w));
// graph[v].push_back(P(u, cur_w));
// }
// vector<ll> dis(n+1, 1e18);
// dis[s] = 0;
// priority_queue<P, vector<P>, compare> pq;
// pq.push(P(s, 0));
// while(pq.size()){
// P u= pq.top(); pq.pop();
// for(P v: graph[u.i]) if (minimize(dis[v.i], dis[u.i] + v.w))
// pq.push(P(v.i, dis[v.i]));
// }
// return dis[t];
// }
// void answer(int _x, int _y){
// x = _x, y = _y;
// }
void find_pair(int _n, vector<int> U, vector<int> V, int A, int B) {
n = _n, m = U.size();
for(int i = 0; i<n; ++i) {
graph[i].clear();
DAG[i].clear();
}
ll initial = ask(vector<int>(m));
int l = 0, r = m - 1;
while(l < r){
int mid = (l + r) >> 1;
vector<int> w(m);
for(int i = 0; i<=mid; ++i) w[i] = 1;
if (ask(w) > initial) r = mid;
else l = mid + 1;
}
if (l == m - 1) {
answer(U[l], V[l]);
return;
}
for(int i = l + 1; i<m; ++i){
int u = U[i], v = V[i];
graph[u].push_back({v, i});
graph[v].push_back({u, i});
}
int u = U[l], v = V[l];
vector<int> dis(n, 1e9);
dis[u] = dis[v] = 0;
deque<int> q; q.push_back(u); q.push_back(v);
while(q.size()){
int u= q.front(); q.pop_front();
if (dis[u] == initial / A - 1) continue;
for(pair<int, int> v: graph[u]) if (minimize(dis[v.first], dis[u] + 1)){
q.push_back(v.first);
DAG[u].push_back(v);
}
}
vector<int> S1, S2;
dfs(u, S1); dfs(v, S2);
vector<int> S = S1;
for(int i: S2) S.push_back(i);
remove_dup(S);
vector<int> _w(m);
for(int i = 0; i<m; ++i){
if (!binary_search(ALL(S), i)) _w[i] = 1;
}
_w[l] = 0;
int x, y;
l = 0, r = S1.size();
while(l < r){
int mid = (l + r) >> 1;
vector<int> w = _w;
for(int i = 0; i<=mid; ++i) w[S1[i]] = 1;
if (ask(w) > initial) r = mid;
else l = mid + 1;
}
if (l == S1.size()) x = u;
else{
if (dis[U[S1[l]]] > dis[V[S1[l]]]) x = U[S1[l]];
else x = V[S1[l]];
}
l = 0, r = S2.size();
while(l < r){
int mid = (l + r) >> 1;
vector<int> w = _w;
for(int i = 0; i<=mid; ++i) w[S2[i]] = 1;
if (ask(w) > initial) r = mid;
else l = mid + 1;
}
if (l == S2.size()) y = v;
else{
if (dis[U[S2[l]]] > dis[V[S2[l]]]) y = U[S2[l]];
else y = V[S2[l]];
}
answer(x, y);
}
// pair<bool, int> solve(int _n, int _m){
// n = _n, m = _m;
// U.clear(); V.clear();
// x = y = -1;
// o_cnt = 0;
// for(int i= 1; i<n; ++i){
// U.push_back(rngesus(0, i-1));
// V.push_back(i);
// if (rngesus(0, 1)) swap(U.back(), V.back());
// }
// for(int i = n; i<=m; ++i){
// int u = rngesus(0, n-1);
// int v = u;
// while(u == v) v = rngesus(0, n-1);
// U.push_back(u);
// V.push_back(v);
// }
// s = rngesus(0, n-1);
// t = s;
// while(t == s) t = rngesus(0, n-1);
// A = 1, B = 2;
// find_pair(n, U, V, A, B);
// if (x > y) swap(x, y);
// if (s > t) swap(s, t);
// return make_pair(make_pair(x, y) == make_pair(s, t), o_cnt);
// }
// }
// int main(void){
// ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
// for(int iteration = 1; iteration <= 100; ++iteration){
// pair<bool, int> verdict = Grader::solve(100, rngesus(99, 111));
// if (verdict.first) cout << "AC\n";
// else cout << "WA\n";
// cout << "Operation count: " << verdict.second << "\n";
// if (verdict.first == false) break;
// }
// return 0;
// }
