#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ii = pair<int, int>;
const ll INF = 1e18;
const int MAX_N = 3000;
vector<ii> adj[MAX_N];
void dfs(int u, vector<ll> &dist, int p = -1, ll d = 0) {
dist[u] = d;
for (auto [v, w] : adj[u]) {
if (v != p) dfs(v, dist, u, d + w);
}
}
int max_score(int N, int X, int Y, ll K, vector<int> U, vector<int> V, vector<int> W) {
for (int i = 0; i < N; i++) adj[i].clear();
for (int i = 0; i < N - 1; i++) {
adj[U[i]].emplace_back(V[i], W[i]);
adj[V[i]].emplace_back(U[i], W[i]);
}
vector<ll> distToX(N), distToY(N);
dfs(X, distToX), dfs(Y, distToY);
vector<ll> val[2], pref[2];
for (int i = 0; i < 2; i++) {
val[i].resize(N);
pref[i].assign(N + 1, 0);
}
for (int i = 0; i < N; i++) {
tie(val[0][i], val[1][i]) = minmax(distToX[i], distToY[i]);
val[1][i] -= val[0][i];
for (int j = 0; j < 2; j++) {
pref[j][i + 1] = pref[j][i] + val[j][i];
}
}
int ans = 0;
for (int i = 0; i <= X; i++) {
for (int j = Y; j < N; j++) {
ll sum = pref[0][j + 1] - pref[0][i];
for (int k = X + 1; k < Y; k++) {
int lo = k - 2, hi = Y;
while (lo + 1 < hi) {
int mid = (lo + hi) / 2;
if (sum - pref[0][mid + 1] + pref[0][k] <= K) hi = mid;
else lo = mid;
}
if (hi != Y) {
ans = max(ans, (j - i + 1) - (hi - k + 1));
}
}
for (int k = i; k <= j; k++) {
int lo = k - 2, hi = j + 1;
while (lo + 1 < hi) {
int mid = (lo + hi) / 2;
if (sum + pref[1][mid + 1] - pref[1][k] <= K) lo = mid;
else hi = mid;
}
if (lo != k - 2) {
ans = max(ans, (j - i + 1) + (lo - k + 1));
}
}
}
}
return ans;
}
