#include <bits/stdc++.h>
#include "grader.h"
#define pii pair<int, int>
#define rep(a,b,c) for(int a=b; a<c; a++)
#define repr(a,b,c) for(int a=b-1; a>c-1; a--)
#define repa(a,b) for(auto a:b)
#define all(a) a.begin(), a.end()
#define fi first
#define se second
#define mid ((l+r+1)>>1)
#define pb push_back
using namespace std;
using vi = vector<int>;
const int N=555;
vi adj[N];
int lvl[N];
void dfs(int u, int p){
lvl[u]=lvl[p]+1;
repa(v,adj[u]) if(v!=p) dfs(v,u);
}
int findEgg (int N, vector < pair < int, int > > bridges){
rep(i,1,N+1) adj[i].clear();
repa(e,bridges){
adj[e.fi].pb(e.se);
adj[e.se].pb(e.fi);
}
dfs(1,0);
vector<pii> nd;
rep(i,1,N+1) nd.pb({lvl[i],i});
sort(all(nd));
vi qr;
int x=0, y=N, z;
while(__builtin_popcount(y)>1) y++;
z=__lg(y);
repr(i,z,0){
qr.clear();
int r=min(N-1,(x+(1<<i)));
rep(j,0,r) qr.pb(nd[j].se);
if(!query(qr)) x=r;
}
return nd[x].se;
}
