// #include "closing.h"
#include <bits/stdc++.h>
using namespace std;
// #pragma GCC optimize ("Ofast")
// #pragma GCC target ("avx2")
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
#define el << '\n'
#define nl cout << '\n'
#define spc << ' '
#define forn(i,n) for (int i=0; i<n; i++)
#define forl(i,s,e) for (int i=s; i<e; i++)
#define pb push_back
#define fi first
#define se second
#define rsz resize
#define sz(x) ((int) x.size())
#define all(x) x.begin(), x.end()
const int inf = 1000000000;
const ll inf2 = 4000000000000000000;

const int MAXN = 200005;
vector<pii> adj[MAXN];
pll dis[MAXN];

int nc(int N, int X, int Y, ll K) {
	bool u[N];
	forn(i,N) u[i] = false;
	priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> pq;
	pq.push({0,X});
	pq.push({0,Y});
	int tot = 0;
	while (sz(pq)) {
		auto cn = pq.top();
		pq.pop();
		if (cn.fi > K) break;
		if (u[cn.se]) continue;
		K -= cn.fi;
		tot++;
		u[cn.se] = true;
		for (pii i : adj[cn.se]) {
			if (!u[i.fi]) pq.push({cn.fi + i.se, i.fi});
		}
	}
	return tot;
}

vector<int> fp;
vector<int> anc;

void dfs(int cn, int pn, int tn) {
	anc.pb(cn);
	if (cn == tn) {
		for (int i : anc) fp.pb(i);
	}
	for (pii i : adj[cn]) {
		if (i.fi != pn) dfs(i.fi, cn, tn);
	}
	anc.pop_back();
}

int max_score(int N, int X, int Y, ll K, vector<int> U, vector<int> V, vector<int> W) {
	forn(i,N) adj[i].clear();
	fp.clear();
	anc.clear();
	struct st {
		int cn, pn; ll d; bool p;
	};
	forn(i,N-1) {
		adj[U[i]].pb({V[i], W[i]});
		adj[V[i]].pb({U[i], W[i]});
	}
	int ans = nc(N, X, Y, K);
	vector<st> stk;
	stk.pb({X, -1, 0, 0});
	while (sz(stk)) {
		st a = stk.back();
		stk.pop_back();
		if (a.p) dis[a.cn].se = a.d;
		else dis[a.cn].fi = a.d;
		for (pii i : adj[a.cn]) if (i.fi != a.pn) stk.pb({i.fi, a.cn, a.d+i.se, a.p});
	}
	stk.pb({Y, -1, 0, 1});
	while (sz(stk)) {
		st a = stk.back();
		stk.pop_back();
		if (a.p) dis[a.cn].se = a.d;
		else dis[a.cn].fi = a.d;
		for (pii i : adj[a.cn]) if (i.fi != a.pn) stk.pb({i.fi, a.cn, a.d+i.se, a.p});
	}
	forn(i,N) if (dis[i].fi < dis[i].se) swap(dis[i].fi, dis[i].se);
	dfs(X, -1, Y);
	int ans2 = 0;
	for (int i : fp) {
		K -= dis[i].se;
		ans2++;
		dis[i].se = dis[i].fi - dis[i].se;
		dis[i].fi = inf2;
	}
	if (K<0) return ans;
	int ans3 = 0;
	sort(dis,dis+N);
	// forn(i,N) cout << dis[i].fi spc << dis[i].se el;
	// nl;
	int cv = 0;
	ll la = K;
	ll cs = 0;
	set<pair<ll, int>> cu;
	set<pair<ll, int>> ca;
	forn(i,N) ca.insert({dis[i].se, i});
	while (1) {
		if (!sz(ca)) break;
		auto temp = *ca.begin();
		if (cs + temp.fi > la) break;
		cv++;
		cs += temp.fi;
		cu.insert(temp);
		ca.erase(temp);
	}
	ans3 = cv;
	ll rs = 0;
	forn(i,N) {
		if (cu.find({dis[i].se, i}) == cu.end()) ca.erase({dis[i].se, i});
		else {
			cu.erase({dis[i].se, i});
			cv--;
			cs -= dis[i].se;
		}
		if (i) {
			cu.insert({dis[i-1].fi - dis[i-1].se, i-1});
			cs += dis[i-1].fi;
			cv++;
		}
		if (rs + dis[i].fi > K) break;
		la = K - dis[i].fi;
		while (cs > la) {
			if (!sz(cu)) break;
			auto temp = *(--cu.end());
			cu.erase(temp);
			ca.insert(temp);
			cs -= temp.fi;
			cv--;
		}
		while (1) {
			if (!sz(ca)) break;
			auto temp = *(ca.begin());
			if (cs + temp.fi > la) break;
			cs += temp.fi;
			ca.erase(temp);
			cu.insert(temp);
			cv++;
		}
		if (cs > la) break;
		ans3 = max(ans3, cv + 2);
		rs += dis[i].se;
	}
	// cout << ans spc << ans2 spc << ans3 el;
	return max(ans, ans2+ans3);
}