#include <bits/stdc++.h>
#include "grader.h"
using namespace std;
vector<int> a;
vector<vector<int>> g;
void dfs(int u, int p) {
a.push_back(u);
for (auto v : g[u]) {
if (v != p) dfs(v, u);
}
}
int findEgg (int N, vector<pair<int, int>> bridges) {
a.clear();
g.assign(N + 1, vector<int>());
for (auto [u, v] : bridges) {
g[u].push_back(v);
g[v].push_back(u);
}
dfs(1, 0);
int l = 0, r = N;
while (l + 1 < r) {
int m = (l + r) / 2;
if (query({a.begin(), a.begin() + m})) {
r = m;
}
else {
l = m;
}
}
return a[l];
}
