#include "highway.h"
#include <bits/stdc++.h>
typedef long long ll;
//namespace Q {
//int N = 4;
//std::vector <int> U = { 0, 0, 0 };
//std::vector <int> V = { 1, 2, 3 };
//int A = 1, B = 2;
//int s = 2, e = 3;
//};
//ll ask(std::vector <int> v) {
//ll ret =
//return 0;
//}
//void answer(int s, int t) {
//std::cerr << "answered: (" << s << ", " << t << ")" << std::endl;
//std::cerr << "answer was(" << Q::s << ", " << Q::e << ")" << std::endl;
//}
std::vector <std::vector <int>> g;
int dfs(int B, std::vector <int>& v, int length, int node = 0, int par = -1, int d = 0) {
v[node] = 1;
if (d == length) {
ll now = ask(v);
if (now == ll(B) * ll(length)) return node;
return -1;
}
for (int x : g[node]) if (x != par) {
int now = dfs(B, v, length, x, node, d + 1);
if (now != -1) return now;
}
v[node] = 0;
return -1;
}
void find_pair(int n, std::vector <int> U, std::vector <int> V, int A, int B) {
g.resize(n);
for (int i = 0; i < n - 1; i++) {
g[U[i]].push_back(V[i]);
g[V[i]].push_back(U[i]);
}
std::vector <int> v(n, 0);
int length = ask(v) / ll(A);
answer(1, dfs(B, v, length) + 1);
}
//int main() {
//}
