#include <bits/stdc++.h>
using namespace std;
vector<int> st;
vector<vector<int>> adj;
void dfs(int u, int p) {
st.push_back(u);
for(int v : adj[u]) {
if(v == p)
continue;
dfs(v, u);
}
}
int query(vector<int> islands);
int findEgg(int N, vector<pair<int,int>> bridges) {
adj.clear();
adj.resize(N + 1);
for(auto[u, v] : bridges) {
adj[u].push_back(v);
adj[v].push_back(u);
}
st.clear();
dfs(1, -1);
int l = 1, r = N, res = 0;
while(l <= r) {
int m = (l + r) / 2;
if(query(vector<int>(st.begin(), st.begin() + m))) {
res = st[m - 1];
r = m - 1;
} else {
l = m + 1;
}
}
return res;
}
