//Challenge: Accepted
#include <iostream>
#include <algorithm>
#include <utility>
#include <vector>
#include "grader.h"
#define ll long long
#define maxn 550
#define ff first
#define ss second
#define io ios_base::sync_with_stdio(0);cin.tie(0);
#define pii pair<int, int>
using namespace std;
//#include <bits/extc++.h>
//using namespace __gnu_pbds;
//template<lcass T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
//find by order, order of key
namespace{
vector<int> adj[maxn];
vector<int> que;
bool found[maxn];
bool poss[maxn], cost[maxn];
}
void dfs(int n, int par, int &num) {
if (num == 0) return;
num -= cost[n];
found[n] = 1;
que.push_back(n);
for (int v:adj[n]) {
if (v != par) {
dfs(v, n, num);
}
}
}
int findEgg(int n, vector < pair < int, int > > bridges) {
for (int i = 1;i <= n;i++) poss[i] = 1, cost[i] = 1, adj[i].clear();
for (auto ed:bridges) {
adj[ed.ff].push_back(ed.ss);
adj[ed.ss].push_back(ed.ff);
}
int cur = n;
while (true) {
if (cur == 1) {
for (int i = 1;i <= n;i++) {
if (poss[i]) return i;
}
break;
}
for (int i = 1;i <= n;i++) found[i] = 0;
que.clear();
int num = cur / 2;
cur -= num;
dfs(1, 0, num);
//cout << endl;
int val = query(que);
if (val) {
for (int i = 1;i <= n;i++) {
if (!found[i]) cost[i] = 0, poss[i] = 0;
}
} else {
for (int i = 1;i <= n;i++) {
if (found[i]) cost[i] = 0, poss[i] = 0;
}
}
}
return -1;
}
/*
5
1 2
1 3
2 4
3 5
5
1 2 3 4 5
*/
