#include "bits/stdc++.h"
using namespace std;
#ifdef _DEBUG
#include "dump.hpp"
#else
#define dump(...)
#endif

#define int long long
#define rep(i,a,b) for(int i=(a);i<(b);i++)
#define rrep(i,a,b) for(int i=(b)-1;i>=(a);i--)
#define all(c) begin(c),end(c)
const int INF = sizeof(int) == sizeof(long long) ? 0x3f3f3f3f3f3f3f3fLL : 0x3f3f3f3f;
const int MOD = 1'000'000'007;
template<class T> bool chmax(T &a, const T &b) { if (a < b) { a = b; return true; } return false; }
template<class T> bool chmin(T &a, const T &b) { if (b < a) { a = b; return true; } return false; }

using Weight = int;
struct Edge {
	int s, d; Weight w;
	Edge() {};
	Edge(int s, int d, Weight w) : s(s), d(d), w(w) {};
};
bool operator<(const Edge &e1, const Edge &e2) { return e1.w == e2.w ? (e1.s == e2.s ? e1.d < e2.d : e1.s < e2.s) : e1.w < e2.w; }
bool operator>(const Edge &e1, const Edge &e2) { return e2 < e1; }
inline ostream &operator<<(ostream &os, const Edge &e) { return (os << '(' << e.s << ", " << e.d << ", " << e.w << ')'); }

using Edges = vector<Edge>;
using Graph = vector<Edges>;
using Array = vector<Weight>;
using Matrix = vector<Array>;

void addArc(Graph &g, int s, int d, Weight w = 1) {
	g[s].emplace_back(s, d, w);
}
void addEdge(Graph &g, int a, int b, Weight w = 1) {
	addArc(g, a, b, w);
	addArc(g, b, a, w);
}

auto getEdges = [](const Graph &g) {
	Edges ret;
	for (auto &es : g)
		for (auto &e : es)
			ret.emplace_back(e);
	return ret;
};

struct UnionFind {
	vector<int> parent;
	int size;
	UnionFind(int n) :parent(n, -1), size(n) {}
	bool unite(int x, int y) {
		x = root(x); y = root(y);
		if (x == y)return false;
		if (sizeOf(x) < sizeOf(y))swap(x, y);
		parent[x] += parent[y]; parent[y] = x; size--;
		return true;
	}
	bool same(int x, int y) { return root(x) == root(y); }
	int root(int x) { return parent[x] < 0 ? x : parent[x] = root(parent[x]); }
	int sizeOf(int x) { return -parent[root(x)]; }
};

struct Query {
	int u, v;
	Query(int u, int v) :u(u), v(v) {}
};
struct LowestCommonAncestor {
	vector<vector<pair<int, Query>>> query_set;
	Graph g;
	vector<int> color;
	vector<int> ancestor;
	vector<int> res;
	UnionFind uf;
	LowestCommonAncestor(const Graph &g, vector<Query> &query) :g(g), color(g.size()), ancestor(g.size()), uf(g.size()), res(query.size()), query_set(g.size()) {
		int n = query.size();
		for (int i = 0; i < n; i++) {
			query_set[query[i].u].emplace_back(i, query[i]);
			query_set[query[i].v].emplace_back(i, query[i]);
		}
	}
	void visit(int s, int prev) {
		ancestor[uf.root(s)] = s;
		for (auto &e : g[s]) {
			if (e.d == prev)continue;
			visit(e.d, s);
			uf.unite(e.s, e.d);
			ancestor[uf.root(s)] = s;
		}
		color[s] = 1;
		for (auto &p : query_set[s]) {
			Query q = p.second;
			int w = (q.v == s ? q.u : q.u == s ? q.v : -1);
			if (w == -1 || !color[w])continue;
			res[p.first] = ancestor[uf.root(w)];
		}
	}
	vector<int> solve(int root) {
		int n = g.size();
		UnionFind uf(n);
		vector<int> color(n), ancestor(n);
		visit(root, -1);
		return res;
	}
};

auto bfs = [&](const Graph &g, int s, Array &dist) {
	int n = g.size();
	vector<bool> vis(n);
	vector<int> prev(n, -1);
	dist.assign(n, INF); dist[s] = 0;
	using State = tuple<Weight, int, int>;
	queue<State> q;
	q.emplace(0, s, -1);
	while (q.size()) {
		Weight d; int v, p; tie(d, v, p) = q.front(); q.pop();
		vis[v] = true;
		prev[v] = p;
		for (auto &e : g[v]) {
			if (vis[e.d])continue;
			if (dist[e.d] > dist[v] + e.w) {
				dist[e.d] = dist[v] + e.w;
				q.emplace(dist[e.d], e.d, v);
			}
		}
	}
	return prev;
};

// 無向木を anti-arborescence に変換
// 連結無向グラフから変換することも可能
// (親, weight) の配列を返す
vector<pair<int, Weight>> antiArborescence(const Graph &g, int root = 0) {
	int n = g.size();
	vector<bool> vis(n);
	queue<int> q; q.emplace(root);
	vector<pair<int, Weight>> ret(n); ret[root] = make_pair(-1, 0);
	while (q.size()) {
		int u = q.front(); q.pop();
		if (vis[u])continue;
		vis[u] = true;
		for (auto &e : g[u]) {
			if (vis[e.d])continue;
			ret[e.d] = make_pair(u, e.w);
			q.emplace(e.d);
		}
	}
	return ret;
}

signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	int N; cin >> N;
	Graph g(N);
	vector<int> A(N - 1), B(N - 1); rep(i, 0, N - 1) {
		cin >> A[i] >> B[i];
		addEdge(g, A[i], B[i]);
	}
	vector<int> U(N); rep(i, 0, N) {
		cin >> U[i];
	}
	int M; cin >> M;
	vector<Query> q;
	vector<int> a(M), b(M), c(M); rep(i, 0, M) {
		cin >> a[i] >> b[i] >> c[i];
		q.emplace_back(a[i], b[i]);
	}
	LowestCommonAncestor lca(g, q);
	vector<int> res = lca.solve(0);

	auto t = antiArborescence(g, 0);
	Graph g2(N);
	rep(i, 1, N) {
		int p = t[i].first;
		addEdge(g2, i, p, U[i]);
	}
	Array dist;
	bfs(g2, 0, dist);


	int ans = 0;
	rep(i, 0, M) {
		int anc = res[i];
		ans += (dist[a[i]] + dist[b[i]] - 2 * dist[anc] + U[anc]) * c[i];
	}
	cout << ans << endl;

	return 0;
}