#include "chameleon.h"
#include <bits/stdc++.h>
#define sz(x) (int)(x).size()
#define vi vector<int>
#define trav(x, a) for (const auto& x: a)
#define pb push_back
using namespace std;
const int N = 1005;
vector<int> adj[N], lv[N];
void Solve(int n) {
for (int i = 1; i <= 2*n; i++) {
vi c[2], vis(i+1, 0);
function<void(int,int)> dfs = [&](int u, int f){
c[f/2].pb(u); vis[u] = 1;
trav(v, adj[u])
if (!vis[v])
dfs(v, f^2);
};
for (int j = 1; j < i; j++)
if (!vis[j])
dfs(j, 1);
for (int j = 0; j < 2; j++) {
vi ask = c[j];
while (1) {
ask.pb(i);
if (Query(ask) == sz(ask))
break;
ask.pop_back();
int lo = 0, hi = sz(ask)-1;
while (lo <= hi) {
int mi = (lo+hi) / 2;
vi tmp;
for (int k = 0; k <= mi; k++)
tmp.pb(ask[k]);
tmp.pb(i);
if (Query(tmp) != sz(tmp))
hi = mi - 1;
else
lo = mi + 1;
}
adj[i].pb(ask[lo]);
adj[ask[lo]].pb(i);
vi tmp;
for (int i = lo+1; i < sz(ask); i++)
tmp.pb(ask[i]);
swap(tmp, ask);
}
}
}
for (int i = 1; i <= 2*n; i++) {
if (sz(adj[i]) == 1) {
if (adj[i][0] < i)
Answer(adj[i][0], i);
continue;
}
trav(x, adj[i]) {
vector<int> tmp = {i};
trav(y, adj[i]) {
if (x != y)
tmp.pb(y);
}
if (Query(tmp) == 1) {
lv[i].pb(x); // ->
lv[x].pb(i); // <-
break;
}
}
}
for (int i = 1; i <= 2*n; i++) {
if (sz(adj[i]) == 1)
continue;
set<int> tmp(lv[i].begin(), lv[i].end());
trav(x, adj[i]) {
if (tmp.count(x))
continue;
if (i > x) // !
Answer(i, x);
}
}
}
