// In the name of Allah
#include <bits/stdc++.h>
#include "closing.h"
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define F first
#define S second
#define endl '\n'
#define sep ' '
#define pb push_back
#define Mp make_pair
#define all(x) (x).begin(),(x).end()
#define len(x) ((ll) (x).size())
const int maxn = 4e5 + 7;
int n, u1, u2; ll R;
vector<pll> adj[maxn];
ll val[maxn], val1[maxn], val2[maxn];
ll sm1[maxn], sm2[maxn], mn1[maxn], mn2[maxn];
vector<ll> ls1; vector<pll> ls2;
void dfs(int v, int p = -1) {
for (auto f : adj[v]) {
int u = f.F; ll w = f.S;
if (u == p) continue;
val[u] = val[v] + w;
dfs(u, v);
}
}
int cal(ll R) {
sort(all(ls1)); sort(all(ls2));
for (int i = 0; i < len(ls1); i++) {
if (i == 0) sm1[i] = ls1[i];
else sm1[i] = sm1[i - 1] + ls1[i];
}
for (int i = 1; i <= len(ls2); i++) {
sm2[i] = sm2[i - 1] + ls2[i - 1].F;
}
for (int i = 0; i < len(ls2); i++) {
mn1[i] = ls2[i].S - ls2[i].F; mn2[i] = ls2[i].S;
}
for (int i = 1; i < len(ls2); i++) mn1[i] = min(mn1[i], mn1[i - 1]);
for (int i = len(ls2) - 2; i >= 0; i--) mn2[i] = min(mn2[i], mn2[i + 1]);
int ans = 0;
for (int i = 0; i <= 2 * len(ls2); i++) {
int x = i, j = i / 2;
if (i % 2 == 0) {
ll w = R - sm2[j];
if (w >= 0) {
x += upper_bound(sm1, sm1 + len(ls1), w) - sm1;
ans = max(ans, x);
}
}
else {
ll wx = min(mn1[j] + ls2[j].F, mn2[j]);
ll w = R - sm2[j] - wx;
if (w >= 0) {
x += upper_bound(sm1, sm1 + len(ls1), w) - sm1;
ans = max(ans, x);
}
}
}
return ans;
}
int max_score(int N, int X, int Y, long long K, vector<int> U, vector<int> V, vector<int> W) {
n = N; u1 = X; u2 = Y; R = K;
for (int i = 0; i < n; i++) adj[i].clear();
for (int i = 0; i < n - 1; i++) {
int u = U[i], v = V[i]; ll w = W[i];
adj[u].pb(Mp(v, w)); adj[v].pb(Mp(u, w));
}
val[u1] = 0; dfs(u1);
for (int i = 0; i < n; i++) val1[i] = val[i];
val[u2] = 0; dfs(u2);
for (int i = 0; i < n; i++) val2[i] = val[i];
for (int i = 0; i < n; i++) {
if (2 * min(val1[i], val2[i]) <= max(val1[i], val2[i])) {
ls1.pb(min(val1[i], val2[i]));
ls1.pb(max(val1[i], val2[i]) - min(val1[i], val2[i]));
}
else {
ls2.pb(Mp(max(val1[i], val2[i]), min(val1[i], val2[i])));
}
}
int ans = 0;
ls1.clear(); ls2.clear();
for (int i = 0; i < n; i++) {
ls1.pb(min(val1[i], val2[i]));
}
ans = max(ans, cal(R));
ls1.clear(); ls2.clear();
int x = 0; ll valx = R;
for (int i = 0; i < n; i++) {
if (val1[i] + val2[i] == val1[u2]) {
valx -= min(val1[i], val2[i]); x++;
ls1.pb(max(val1[i], val2[i]) - min(val1[i], val2[i]));
}
else {
if (2 * min(val1[i], val2[i]) <= max(val1[i], val2[i])) {
ls1.pb(min(val1[i], val2[i]));
ls1.pb(max(val1[i], val2[i]) - min(val1[i], val2[i]));
}
else {
ls2.pb(Mp(max(val1[i], val2[i]), min(val1[i], val2[i])));
}
}
}
if (valx >= 0) ans = max(ans, x + cal(valx));
return ans;
}
