// In the name of Allah
#include <bits/stdc++.h>
#include "highway.h"
using namespace std;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef complex<ld> cld;
#define all(x) (x).begin(),(x).end()
#define len(x) ((ll) (x).size())
#define F first
#define S second
#define pb push_back
#define sep ' '
#define endl '\n'
#define Mp make_pair
#define kill(x) cout << x << '\n', exit(0)
#define set_dec(x) cout << fixed << setprecision(x);
#define file_io(x,y) freopen(x, "r", stdin); freopen(y, "w", stdout);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int maxn = 2e5 + 4;
const int oo = 1e9 + 7;
int n, m; ll D;
vector<int> adj[maxn], ls;
vector<pii> E; bool M[maxn];
int arr[maxn], dis[maxn];
queue<int> qu;
void bfs(int v) {
fill(dis, dis + n, oo);
dis[v] = 0; qu.push(v);
while (!qu.empty()) {
v = qu.front(); qu.pop();
for (int u : adj[v]) {
if (dis[v] + 1 < dis[u]) {
dis[u] = dis[v] + 1;
qu.push(u);
}
}
}
}
bool cmp(int i, int j) {
return (dis[i] < dis[j]);
}
ll askx() {
ls.clear(); ls.resize(m);
for (int i = 0; i < m; i++) {
int u = E[i].F, v = E[i].S;
if (M[u] || M[v]) ls[i] = 1;
else ls[i] = 0;
}
return ask(ls);
}
int getv(vector<int> vc) {
if (len(vc) == 1) return vc[0];
vector<int> vc1, vc2;
int mid = (len(vc) / 2);
for (int i = 0; i < mid; i++) vc1.pb(vc[i]);
for (int i = mid; i < len(vc); i++) vc2.pb(vc[i]);
for (int u : vc1) M[u] = 1;
if (askx() == D) return getv(vc2);
else {
for (int u : vc1) M[u] = 0;
return getv(vc1);
}
}
int getx() {
iota(arr, arr + n, 0); sort(arr, arr + n, cmp);
int l = 0, r = n;
while (r - l > 1) {
int mid = (l + r) / 2;
for (int j = 0; j < n; j++) {
M[arr[j]] = (j >= mid);
}
if (askx() > D) l = mid;
else r = mid;
}
return arr[l];
}
void find_pair(int Nx, vector<int> ux, vector<int> vx, int A, int B) {
n = Nx; m = len(ux);
for (int i = 0; i < m; i++) {
int u = ux[i], v = vx[i];
adj[u].pb(v); adj[v].pb(u);
E.pb(Mp(u, v));
}
D = askx();
vector<int> vc;
for (int i = 0; i < n; i++) {
M[i] = 0; vc.pb(i);
}
int vr = getv(vc);
bfs(vr); int u1 = getx();
bfs(u1); int u2 = getx();
answer(u1, u2);
}
