#include "highway.h"
#include<bits/stdc++.h>
#define ll long long
#define pii pair<ll,ll>
#define x first
#define y second
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
vector<pii>g[90015];
vector<ll>all[90015][2],root[2];
vector<int>qry;
ll n,m,mx[2],mn,a,b,d,fa[90015],dep[90015];
void bfs(int r1,int r2){
for (int i=0;i<=n;i++){
fa[i]=0; dep[i]=0; mx[0]=1; mx[1]=1;
all[i][0].clear();
all[i][1].clear();
}
queue<pii>q;
q.push({r1,0}); q.push({r2,1});
dep[r1]=1; dep[r2]=1;
fa[r1]=-1; fa[r2]=-1;
while (!q.empty()){
auto [p,rt]=q.front(); q.pop();
root[rt].push_back(p);
all[dep[p]][rt].push_back(p);
mx[rt]=max(mx[rt],dep[p]);
for (auto [i,idx]:g[p]){
if (!dep[i]){
dep[i]=dep[p]+1; fa[i]=idx;
qry[fa[i]]=0;
q.push({i,rt});
}
}
}
}
int find(int f,int p){
if (p==1) return all[p][f][0];
for (auto i=2;i<=n;i++){
for (auto j:all[i][f^1])
qry[fa[j]]=1;
}
for (int i=2;i<=n;i++){
if (p!=i){
for (auto j:all[i][f])
qry[fa[j]]=1;
}
}
ll l=0,r=all[p][f].size();
while (l<r){
int mid=(l+r)>>1;
for (int j=l;j<=mid;j++)
qry[fa[all[p][f][j]]]=1;
ll dis=ask(qry);
for (int j=l;j<=mid;j++)
qry[fa[all[p][f][j]]]=0;
if (dis==mn+d*(b-a)) r=mid;
else l=mid+1;
}
for (auto i=2;i<=n;i++){
for (auto j:all[i][f^1])
qry[fa[j]]=0;
}
for (int i=2;i<=n;i++){
if (p!=i){
for (auto j:all[i][f])
qry[fa[j]]=0;
}
}
return all[p][f][l];
}
void solve1(int u,int v,int _i){
fill(qry.begin(),qry.end(),1);
qry[_i]=0;
bfs(u,v);
for (int i=0;i<=n;i++){
for (auto j:all[i][0]){
if (fa[j]!=-1) qry[fa[j]]=1;
}
}
ll ldep=ask(qry);
for (int i=0;i<=n;i++){
for (auto j:all[i][0]){
if (fa[j]!=-1) qry[fa[j]]=0;
}
}
ldep=(ldep-mn)/(b-a); qry[_i]=1;
int s=find(0,ldep+1);
int t=find(1,d-ldep);
answer(s,t);
return;
}
void find_pair(int N, std::vector<int> U, std::vector<int> V, int A, int B) {
n=N; m=U.size(); a=A; b=B;
for (int i=0;i<m;i++){
g[U[i]].push_back({V[i],i});
g[V[i]].push_back({U[i],i});
}
qry.resize(m,0);
mn=ask(qry); d=mn/A;
int l=0,r=m-1,u,v;
while (l<r){
int mid=(l+r)>>1;
for (int i=l;i<=mid;i++)
qry[i]=1;
ll now=ask(qry);
for (int i=l;i<=mid;i++)
qry[i]=0;
if (now!=mn) r=mid;
else l=mid+1;
}
u=U[l]; v=V[l];
solve1(u,v,l);
}
/*
./rand
./highway
4 4 1 3 1 3
0 1
0 2
0 3
1 2
*/
