#include <bits/stdc++.h>
#include "meetings.h"
using namespace std;
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) begin(a),end(a)
const int mxN = (int)2e3+10;
int n, used[mxN];
set<int> S[mxN];
void mergeSort(vector<int> &v, int a, int b){
if(sz(v)<=1) return;
int mid = sz(v)/2;
vector<int> w,x; w.clear(), x.clear();
for(int i = 0; i < mid; i++) w.pb(v[i]);
for(int i = mid; i < sz(v); i++) x.pb(v[i]);
mergeSort(w,a,b), mergeSort(x,a,b); v.clear();
int i = 0, j = 0;
while(i<sz(w) and j<sz(x)){
if(Query(a,w[i],x[j])==w[i]) v.pb(w[i++]);
else v.pb(x[j++]);
}
while(i<sz(w)) v.pb(w[i++]);
while(j<sz(x)) v.pb(x[j++]);
}
void bridge(int a, int b){
if(a>b) swap(a,b);
return Bridge(a,b);
}
void recur(int a, set<int> SS){
if(SS.empty()) return;
auto itr = SS.begin();
int r = rand()%sz(SS);
while(r--) itr++;
int b = *itr; used[a]=used[b]=1;
vector<int> path; path.clear();
set<int> S[n+1];
for(int i = 0; i < n; i++) S[i].clear();
for(auto i : SS){ if(!used[i]){
int x = Query(a,b,i);
if(x==i) path.pb(i),used[i]=1;
else S[x].insert(i);
} }
mergeSort(path,a,b);
if(path.empty()) bridge(a,b);
else bridge(a,path[0]),bridge(path.back(),b);
for(int i = 0; i < sz(path)-1; i++) bridge(path[i],path[i+1]);
for(auto u : path) recur(u,S[u]);
recur(a,S[a]); recur(b,S[b]);
}
void Solve(int N) {
n = N; vector<int> v;
for(int i = 1; i < n; i++) S[0].insert(i);
recur(0,S[0]);
}
