#include "highway.h"
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define vi vector<int>
#define ff first
#define ss second
#define ll long long int
#define pii pair<int,int>
const int N = 2e5+100;
int s[N], dep[N], PAR[N];
vector<pii> g[N];
vi D[N];
vi D2[N];
bitset<N> VIS;
vi C[N];
vector<vi> QC[N];
void pre(int v, int p){
s[v] = 1;
for(auto [u, id]: g[v]){
if(!VIS[u] && u != p){
pre(u, v);
s[v] += s[u];
}
}
}
int num;
int centro(int v, int p){
for(auto [u, id]: g[v]){
if(!VIS[u] && u != p){
if(s[u] >= (num+1)/2) return centro(u, v);
}
}
return v;
}
void f(int v, int dep){
pre(v, v);
num = s[v];
v = centro(v, v);
C[dep].pb(v);
vi q;
for(auto [u, id]: g[v]){
if(!VIS[u]){
q.pb(id);
}
}
QC[dep].pb(q);
VIS[v] = 1;
for(auto [u, id]: g[v]){
if(!VIS[u]) f(u, dep + 1);
}
}
void dfs(int v, int p){
s[v] = 1;
D[dep[v]].pb(v);
for(auto [u, id]: g[v]){
if(!VIS[u] && u != p){
PAR[u] = id;
dep[u] = dep[v] + 1;
dfs(u, v);
s[v] += s[u];
}
}
}
void dfs2(int v, int p){
s[v] = 1;
D2[dep[v]].pb(v);
for(auto [u, id]: g[v]){
if(!VIS[u] && u != p){
PAR[u] = id;
dep[u] = dep[v] + 1;
dfs2(u, v);
s[v] += s[u];
}
}
}
void gg(int v, int node, int idd){
pre(v, v);
num = s[v];
v = centro(v, v);
if(v == node){
for(auto [u, id]: g[v]){
if(id == idd){
PAR[u] = id;
dep[u] = 1;
dfs(u, v);
break;
}
}
}
VIS[v] = 1;
for(auto [u, id]: g[v]){
if(!VIS[u]) gg(u, node, idd);
}
}
void ggg(int v, int node, int idd, int idd2){
pre(v, v);
num = s[v];
v = centro(v, v);
if(v == node){
for(auto [u, id]: g[v]){
if(id == idd){
// cerr << u << ' ';
PAR[u] = id;
dep[u] = 1;
dfs(u, v);
}
if(id == idd2){
// cerr << u << ' ';
PAR[u] = id;
dep[u] = 1;
dfs2(u, v);
}
}
}
VIS[v] = 1;
for(auto [u, id]: g[v]){
if(!VIS[u]) ggg(u, node, idd, idd2);
}
}
void find_pair(int n, std::vector<int> U, std::vector<int> V, int A, int B) {
int m = U.size();
for(int i = 0; i < m; ++i){
g[U[i]].pb({V[i], i});
g[V[i]].pb({U[i], i});
}
vi w(m);
ll val = ask(w);
int k = val / A;
f(0, 0);
for(int d = 0; d < 30; ++d){
if(C[d].empty()) assert(false);
w.clear();
w.resize(m);
for(auto vv: QC[d]){
for(int x: vv) w[x] = 1;
}
ll ress = ask(w);
if(ress != val){
// that means we found one centroid which satisfies
// let's bs
int sz = QC[d].size();
int l = 0, r = sz - 2, res = sz - 1;
while(l <= r){
int mid = l+r>>1;
w.clear();
w.resize(m);
for(int i = 0; i <= mid; ++i){
for(int x: QC[d][i]) w[x] = 1;
}
ll y = ask(w);
if(y != val){
res = mid;
r = mid - 1;
}else{
l = mid + 1;
}
}
// now we now the path passes through C
int node = C[d][res];
vi arr = QC[d][res];
sz = QC[d][res].size();
// now we do bit coloring...
// vector<bool> RES;
// for(int bit = 0; (1<<bit) < sz*2; ++sz){
// w.clear();
// w.resize(m);
// for(int j = 0; j < sz; ++j) if(j&(1<<bit)) w[arr[j]] = 1;
// ll y = ask(w);
// RES.pb(y != val);
// }
// int cnt = 0;
// for(auto x: RES) cnt += x;
// cerr << node << '\n';
l = 0, r = sz-2, res = sz-1;
while(l <= r){
int mid = l+r>>1;
w.clear();
w.resize(m);
for(int j = 0; j <= mid; ++j) w[arr[j]] = 1;
ll y = ask(w);
if(y != val){
res = mid;
r = mid - 1;
}else{
l = mid + 1;
}
}
l = 1, r = sz-1;
int res2 = 0;
while(l <= r){
int mid = l+r>>1;
w.clear();
w.resize(m);
for(int j = mid; j < sz; ++j) w[arr[j]] = 1;
ll y = ask(w);
if(y != val){
res2 = mid;
l = mid + 1;
}else{
r = mid - 1;
}
}
// cerr << res << ' ' << res2 << '\n';
// now we now that there aren't many options..
if(res == res2){
// this is nicer tho
// basically s=0 case
VIS = 0;
gg(0, node, arr[res]);
arr = D[k];
sz = arr.size();
l = 0, r = sz - 2, res = sz - 1;
while(l <= r){
int mid = l+r>>1;
w.clear();
w.resize(m);
for(int j = 0; j <= mid; ++j) w[PAR[arr[j]]] = 1;
ll y = ask(w);
if(y != val){
res = mid;
r = mid - 1;
}else{
l = mid + 1;
}
}
answer(node, arr[res]);
// exit(0);
}else{
// cerr << arr[res] << ' ' << res2 << " crap\n";
// now we gotta solve...
VIS = 0;
ggg(0, node, arr[res], arr[res2]);
w.clear();
w.resize(m);
for(int i = 0; i <= n; ++i) for(int x: D[i]) w[PAR[x]] = 1;
ll y = ask(w);
// cerr << y << ' ';
int k1;
for(ll j = 1; j <= n; ++j){
if(j * B + A * (k-j) == y){
k1 = j;
break;
}
}
// cerr << k1 << ' ';
// so now we know both depths
int k2 = k - k1;
arr.clear();
for(int x: D[k1]) arr.pb(x);
sz = arr.size();
l = 0, r = sz - 2, res = sz - 1;
while(l <= r){
int mid = l+r>>1;
w.clear();
w.resize(m);
for(int j = 0; j <= mid; ++j) w[PAR[arr[j]]] = 1;
ll y = ask(w);
if(y != val){
res = mid;
r = mid - 1;
}else{
l = mid + 1;
}
}
int s = arr[res];
arr.clear();
for(int x: D2[k2]) arr.pb(x);
sz = arr.size();
l = 0, r = sz - 2, res = sz - 1;
while(l <= r){
int mid = l+r>>1;
w.clear();
w.resize(m);
for(int j = 0; j <= mid; ++j) w[PAR[arr[j]]] = 1;
ll y = ask(w);
if(y != val){
res = mid;
r = mid - 1;
}else{
l = mid + 1;
}
}
int t = arr[res];
answer(s, t);
}
return;
}
}
// vector<bool> vis(n);
// queue<int> q;
// vi dist(n);
// q.push(0);
// vis[0] = 1;
// vi T, par(n);
// while(!q.empty()){
// int v = q.front(); q.pop();
// if(dist[v] == k) T.pb(v);
// for(auto [u, id]: g[v]){
// if(!vis[u]){
// par[u] = id;
// dist[u] = dist[v] + 1;
// q.push(u);
// vis[u] = 1;
// }
// }
// }
// int l = 0, r = int(T.size()) - 2, res = int(T.size())-1;
// while(l <= r){
// int mid = l+r>>1;
// w.clear();
// w.resize(m, 0);
// for(int i = 0; i <= mid; ++i) w[par[T[i]]] = 1;
// if(ask(w) > val){
// res = mid;
// r = mid - 1;
// }else{
// l = mid + 1;
// }
// }
// answer(0, T[res]);
}
