#include<bits/stdc++.h>
#include "meetings.h"
#define pii pair<int,int>
#define x first
#define y second
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
set<pii>ans;
void DC(deque<int>have,int par){
int n=have.size();
int root=have[rng()%n];
vector<deque<int> >all(20);
/*
cout<<"solve : ";
for (auto i:have)
cout<<i<<" ";
cout<<'\n';
cout<<"root is "<<root<<'\n';
*/
for (auto i:have){
if (i==root) continue;
for (int j=0;j<19;j++){
if (all[j].empty()){
all[j].push_back(i);
break;
}
else {
int w=Query(all[j][0],root,i);
if (w==root) continue;
if (w==i) all[j].push_front(i);
else all[j].push_back(i);
break;
}
}
}
/*
for (int i=0;i<19;i++){
if (!all[i].empty()){
cout<<"son "<<i<<" : ";
for (auto j:all[i])
cout<<j<<" ";
cout<<'\n';
}
}
*/
for (int i=0;i<19;i++){
if (!all[i].empty()){
int a=all[i][0],b=root;
ans.insert({min(a,b),max(a,b)});
DC(all[i],root);
}
}
}
void Solve(int N){
deque<int>dq;
for (int i=0;i<N;i++)
dq.push_back(i);
DC(dq,0);
for (auto i:ans){
// cout<<i.x<<" "<<i.y<<'\n';
Bridge(i.x,i.y);
}
}
