#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define replr(i, a, b) for (int i = int(a); i <= int(b); ++i)
#define reprl(i, a, b) for (int i = int(a); i >= int(b); --i)
#define rep(i, n) for (int i = 0; i < int(n); ++i)
#define mkp(a, b) make_pair(a, b)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VPI;
typedef vector<VI> VVI;
typedef vector<VVI> VVVI;
typedef vector<VPI> VVPI;
typedef pair<ll, ll> PLL;
typedef vector<ll> VL;
typedef vector<PLL> VPL;
typedef vector<VL> VVL;
typedef vector<VVL> VVVL;
typedef vector<VPL> VVPL;
template<class T> T setmax(T& a, T b) {if (a < b) return a = b; return a;}
template<class T> T setmin(T& a, T b) {if (a < b) return a; return a = b;}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template<class T>
using indset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#include "highway.h"
int n, m;
VVPI gp;
VI depth;
VI parind;
void dfs(int u = 0, int pind = -1) {
parind[u] = pind;
for (auto[v, ind] : gp[u]) if (ind != pind) {
depth[v] = depth[u]+1;
dfs(v, ind);
}
}
void find_pair(int N, std::vector<int> U, std::vector<int> V, int A, int B) {
n = N;
m = U.size();
gp = VVPI(n);
rep(i, m) {
gp[U[i]].pb({V[i], i});
gp[V[i]].pb({U[i], i});
}
depth = parind = VI(n);
dfs();
ll base = ask(VI(m));
int d = base/A;
VI b;
rep(u, n) if (depth[u] == d) b.pb(u);
auto f = [&](int x) {
VI W(m);
replr(i, 0, x) W[parind[b[i]]] = true;
return ask(W) > base;
};
int l = -1, r = b.size()-1;
while (l + 1 < r) {
int m = (l + r) / 2;
if (f(m)) r = m;
else l = m;
}
answer(0, b[r]);
}
/*ask(VI w);*/
/*answer(int s, int t)*/
