#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9+7;
const int maxn = 600 + 1;
#define pii pair<int, int>
#define ll long long
#define pq priority_queue
#define se second
#define fi first
int query(vector<int> dao);
vector<int> adj[maxn];
int tour[maxn];
bool vis[maxn];
int m = 0;
vector<int> ask;
void dfs(int u, int p) {
vis[u] = true;
tour[++m] = u;
for(int v : adj[u]) {
if(v != p && !vis[v]){
dfs(v, u);
}
}
}
int findEgg(int n, vector<pii> g) {
for (int i = 1; i <= n; i++) {
adj[i].clear();
vis[i] = false;
}
m = 0;
memset(tour, 0, sizeof(tour));
for(auto [u, v] : g){
adj[u].push_back(v);
adj[v].push_back(u);
}
dfs(1, -1);
int l = 1, r = n - 1, res = n - 1;
while(l <= r) {
int mid = (l + r)/2;
vector<int> ask;
for(int i = 1; i <= mid; i++) {
ask.push_back(tour[i]);
}
int x = query(ask);
if(x) {
res = mid;
r = mid - 1;
} else {
l = mid + 1;
}
}
return tour[res];
}
