//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#include "grader.h"
using namespace std;
vector<int>res;
vector<vector<int>>nums;
map<int,bool>isSeen;
void dfs(int num)
{
isSeen[num]=true,res.push_back(num);
for(int i=0;i<nums[num].size();i++)
{
if(!isSeen[nums[num][i]])
{
dfs(nums[num][i]);
}
}
}
int findEgg(int n,vector<pair<int,int>>Nums)
{
int left=0,right=n-1,middle;
vector<int>_;
res.clear(),nums.clear(),nums.resize(n+1),isSeen.clear();
for(int i=0;i<Nums.size();i++)
{
nums[Nums[i].first].push_back(Nums[i].second),nums[Nums[i].second].push_back(Nums[i].first);
}
dfs(1);
while(left<=right)
{
middle=(left+right)/2,_.clear();
for(int i=0;i<=middle;i++)
{
_.push_back(res[i]);
}
if(!query(_))
{
left=middle+1;
}
else
{
right=middle-1;
}
}
return res[left];
}
