#include <bits/stdc++.h>
#include "grader.h"
int findEgg(int n, vector<pair<int, int>> edg) {
vector<vector<int>> g(n+1);
for (auto [x, y] : edg) g[x].push_back(y), g[y].push_back(x);
vector<int> in(n+1);
int tt = 1;
auto dfs = [&] (auto&& self, int u, int p) -> void {
in[tt] = u;
tt++;
for (auto v : g[u]) {
if (v == p) continue;
self(self, v, u);
}
};
dfs(dfs, 1, 1);
return 1;
int l = 1, r = n, ans = n;
while (l <= r) {
int md = l + (r-l+1)/2;
vector<int> qq;
for (int i = 1; i <= md; ++i) qq.push_back(in[i]);
if (query(qq)) ans = md, l = md+1;
else r = md-1;
}
return in[ans];
}
