#include "highway.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<ll, ll> pl;
typedef vector<ll> vl;
typedef vector<pl> vpl;
typedef vector<vl> vvl;
typedef vector<vpl> vvpl;
typedef pair<int, int> pi;
typedef vector<int> vi;
typedef vector<pi> vpi;
typedef vector<vi> vvi;
typedef vector<vpi> vvpi;
#define rep(i, n) for(int i = 0; i < n; ++i)
#define all(c) (c.begin()), (c.end())
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define csz(c) ((int)c.size())
#define what(x) cout << #x << "= " << x << endl
// apples ORZZZZZZZZZZZZZZZZ
const int maxn = 1e5 + 5;
vpi g[maxn]; int n; ll a; ll b;
vpi rg[maxn];
pi p[maxn];
int d[maxn];
vpi gd[maxn];
ll amnt = 0;
void dfs0(int c, int par=-1, int dd=0) {
d[c] = dd;
for(const auto e : g[c]) {
if(e.fi!=par) {
rg[c].pb(e);
p[e.fi] = {c, e.se};
gd[dd+1].pb(e);
dfs0(e.fi, c, dd+1);
}
}
}
void dfs1(int c, int m, vi& w) {
for(const auto& e : rg[c]) {
if(d[e.fi] <= m) {
w[e.se] = a;
dfs1(e.fi, m, w);
}
}
}
void get_amount() {
vi w; w.resize(n-1, 0);
amnt = ask(w) / a;
}
void find_pair(int N, vi U, vi V, int A, int B) {
/*if(N <= U.size()) {
answer(1, 3);
return;
}
if(A == 16 && B == 20 && N == 5 && U.size() == 4) {
answer(1, 4); return;
}*/
a=A; b=B;
n=N;
rep(i, n-1) {
g[U[i]].pb({V[i], i});
g[V[i]].pb({U[i], i});
}
dfs0(0);
get_amount();
ll l = 0; ll r = gd[amnt].size()-1;
while(l < r) {
ll m = l + (r - l) / 2;
vi w(n-1, 0);
for(int i = l; i <= m; ++i) {
w[gd[amnt][i].se] = 1;
}
ll res = ask(w);
if(res > amnt*a) {
r = m;
} else {
l = m + 1;
}
}
answer(0, gd[amnt][l].fi);
}
