#include <bits/stdc++.h>
#include "grader.h"
using namespace std;
#define pb push_back
#define f first
#define s second
int vis[513],pos[513],ch[513];
int dfs(int n,vector<int>v[513],int idx=1){
vis[idx]=1;
int x=1;
for(int i=0;i<v[idx].size();i++){
if(!vis[v[idx][i]])
x+=dfs(n,v,v[idx][i]);
}
ch[idx]=x;
return x;
}
vector<int> dfs2(int n,vector<int>v[513],int idx=1){
vis[idx]=1;
vector<int> ans;
ans.pb(idx);
for(int i=0;i<v[idx].size();i++){
if(!vis[v[idx][i]]){
vector<int> z=dfs2(n,v,v[idx][i]);
for(int j=0;j<z.size();j++){
ans.pb(z[j]);
}
}
}
return ans;
}
int findEgg (int n, vector<pair<int,int> > edg){
memset(vis,0,sizeof vis);
memset(pos,0,sizeof pos);
vector<int> v[513];
for(int i=0;i<edg.size();i++){
v[edg[i].f].pb(edg[i].s);
v[edg[i].s].pb(edg[i].f);
pos[edg[i].f]=1;
pos[edg[i].s]=1;
}
dfs(n,v,1);
int x=1;
bool bol=1;
vector<int> cur;
while(1){
if(x<1||x>n)
return n/2;
bol=0;
int tk[513]={0};
vector<int> h;
for(int i=1;i<=n;i++){
if(pos[i])
h.pb(i);
}
/*cout<<h.size()<<"\n";
for(int i=0;i<h.size();i++){
cout<<h[i]<<" ";
}
cout<<"cur: "<<cur.size()<<"\n";
for(int i=0;i<cur.size();i++){
cout<<cur[i]<<" ";
}
cout<<"\n";
cout<<"bol: "<<bol<<"\n";*/
if(cur.size()>=h.size()){
if(query(cur)){
//cout<<"cur > h\n";
x=cur[0];
for(int i=0;i<cur.size();i++){
pos[cur[i]]=1;
}
for(int i=0;i<h.size();i++){
pos[h[i]]=0;
}
for(int i=0;i<v[cur[cur.size()-1]].size();i++){
for(int j=0;j<h.size();j++){
if(v[cur[cur.size()-1]][i]==h[j]){
ch[cur[cur.size()-1]]-=ch[h[j]];
v[cur[cur.size()-1]][i]=v[cur[cur.size()-1]][v[cur[cur.size()-1]].size()-1];
//cout<<"deleted: "<<v[cur[cur.size()-1]][v[cur[cur.size()-1]].size()-1]<<"\n";
v[cur[cur.size()-1]].pop_back();
//cout<<"deleted: "<<v[cur[cur.size()-1]][v[cur[cur.size()-1]].size()-1]<<"\n";
}
}
}
}
cur.clear();
continue;
}
//cout<<"\n\n";
if(h.size()==1){
break;
}
for(int i=1;i<=n;i++){
if(pos[i])
vis[i]=0;
else
vis[i]=1;
}
int a=dfs2(n,v,x).size(),b=1;
vector<int> va,vb;
vb.pb(x);
int zz=0;
for(int i=0;i<v[x].size();i++){
if(b+ch[v[x][i]]<a&&pos[v[x][i]]==1){
//cout<<"took: "<<v[x][i]<<" and his children because "<<b<<"+"<<ch[v[x][i]]<<"<"<<a<<"-"<<ch[v[x][i]]<<"\n";
zz++;
memset(vis,0,sizeof vis);
vis[x]=1;
vector<int> z=dfs2(n,v,v[x][i]);
for(int j=0;j<z.size();j++){
vb.pb(z[j]);
tk[z[j]]=1;
}
b+=ch[v[x][i]];
a-=ch[v[x][i]];
}
}
if(zz==0){
//cout<<"a: "<<a<<" element "<<x<<" added to cur ";
cur.pb(x);
pos[x]=0;
for(int i=0;i<v[x].size();i++){
if(pos[v[x][i]]){
x=v[x][i];
break;
}
}
//cout<<"and x became "<<x<<"\n";
continue;
}
for(int i=1;i<=n;i++){
if(pos[i]==1&&!tk[i]){
va.pb(i);
}
}
/*cout<<"va: "<<va.size()<<"\n";
for(int i=0;i<va.size();i++)
cout<<va[i]<<" ";
cout<<"\n";
cout<<"vb: "<<vb.size()<<"\n";
for(int i=0;i<vb.size();i++)
cout<<vb[i]<<" ";
cout<<"\n\n";*/
if(query(vb)){
cur.clear();
bol=0;
memset(pos,0,sizeof pos);
for(int i=0;i<vb.size();i++){
pos[vb[i]]=1;
}
//cout<<"zz: "<<zz<<"\n";
if(zz==1){
for(int i=0;i<v[x].size();i++){
if(pos[v[x][i]]){
cur.pb(x);
pos[x]=0;
x=v[x][i];
//cout<<"x became "<<x<<"\n";
break;
}
}
}
}
else if(cur.empty()||query(va)){
cur.clear();
bol=1;
memset(pos,0,sizeof pos);
for(int i=0;i<va.size();i++){
pos[va[i]]=1;
}
//cout<<"zz: "<<zz<<"\n";
if(x!=1)
zz++;
if(zz==(int)(v[x].size())-1){
for(int i=0;i<v[x].size();i++){
if(pos[v[x][i]]){
pos[x]=0;
x=v[x][i];
break;
}
}
}
}
else{
memset(pos,0,sizeof pos);
for(int i=0;i<cur.size();i++){
pos[cur[i]]=1;
}
x=cur[0];
cur.clear();
}
}
return x;
}
