#include "highway.h"
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define F first
#define S second
const int maxn = 1e5+100;
vector<pair<int,int>> v[maxn];
vector<int> w;
int a,b;
int x;
set<int> s;
int depth[maxn];
void dfs(int node,int par){
if(depth[node]!=x){
if(s.find(node)!=s.end())
s.erase(node);
}
for(auto x : v[node]){
if(x.F==par) continue;
if(w[x.S]==0){
depth[x.F] = depth[node]+a;
}else depth[x.F] = depth[node]+b;
dfs(x.F,node);
}
}
void find_pair(int N, vector<int> U, vector<int> V, int A, int B) {
srand(time(NULL));
int n = N;
a = A;
b = B;
for(int i = 0;i<n;i++){
s.insert(i);
}
int m = U.size();
for(int i = 0;i<m;i++){
int a = U[i];
int b = V[i];
v[a].pb({b,i});
v[b].pb({a,i});
}
int t = 60;
while(t--){
if(s.size()==1) break;
w.clear();
w.resize(m,0);
for(int i = 0;i<n;i++){
depth[i] = 0;
}
for(int j = 0;j<m;j++){
w[j] = rand()%2;
}
x = ask(w);
dfs(0,0);
}
int ans = *s.begin();
answer(0,ans);
}
