#include <bits/stdc++.h>
using namespace std;
using ll = long long;

class heavy_light_decomposition {
	const int n;
	vector<vector<int>> g;
	vector<int> par, head, in, out;
	void dfs1(int rt) {
		vector<int> size(n, 1);
		vector<size_t> iter(n);
		vector<pair<int, int>> stp;
		stp.reserve(n);
		stp.emplace_back(rt, -1);
		while (!stp.empty()) {
			int v = stp.back().first;
			if (iter[v] < g[v].size()) {
				if (g[v][iter[v]] != stp.back().second) {
					stp.emplace_back(g[v][iter[v]], v);
				}
				++iter[v];
				continue;
			}
			par[v] = stp.back().second;
			for (auto& u : g[v]) if (u == par[v]) {
				if (u != g[v].back()) swap(u, g[v].back());
				g[v].pop_back();
				break;
			}
			for (auto& u : g[v]) {
				size[v] += size[u];
				if (size[u] > size[g[v].front()]) swap(u, g[v].front());
			}
			stp.pop_back();
		}
	}
	void dfs2(int rt) {
		int it = 0;
		vector<size_t> iter(n);
		vector<int> st; st.reserve(n);
		st.push_back(rt);
		while (!st.empty()) {
			int v = st.back();
			if (!iter[v]) in[v] = it++;
			if (iter[v] < g[v].size()) {
				int u = g[v][iter[v]];
				head[u] = iter[v] ? u : head[v];
				st.push_back(u);
				++iter[v];
				continue;
			}
			out[v] = it;
			st.pop_back();
		}
	}
public:
	heavy_light_decomposition(int n_)
		: n(n_), g(n), par(n), head(n), in(n), out(n) {}
	heavy_light_decomposition(const vector<vector<int>>& G)
		: n(G.size()), g(G), par(n), head(n), in(n), out(n) {}
	void add_edge(int u, int v) {
		g[u].push_back(v);
		g[v].push_back(u);
	}
	void build(int rt = 0) {
		dfs1(rt);
		head[rt] = rt;
		dfs2(rt);
	}
	int get_id(int v) {
		return in[v];
	}
	void path_query(int u, int v, function<void(int, int)> f) {
		while (true) {
			if (in[u] > in[v]) swap(u, v);
			f(max(in[head[v]], in[u]), in[v] + 1);
			if (head[u] == head[v]) return;
			v = par[head[v]];
		}
	}
};

int main()
{
	ios::sync_with_stdio(false), cin.tie(0);
	int N;
	cin >> N;
	heavy_light_decomposition hl(N);
	for (int i = 0; i < N - 1; i++) {
		int A, B;
		cin >> A >> B;
		hl.add_edge(A, B);
	}
	hl.build();
	vector<ll> u(N), sum(N + 1);
	for (int i = 0; i < N; i++) {
		int U;
		cin >> U;
		u[hl.get_id(i)] = U;
	}
	for (int i = 0; i < N; i++) {
		sum[i + 1] = sum[i] + u[i];
	}
	int M;
	cin >> M;
	ll res = 0;
	while (M--) {
		int A, B;
		ll C;
		cin >> A >> B >> C;
		ll all = 0;
		hl.path_query(A, B, [&](int l, int r) {
			all += sum[r] - sum[l];
		});
		res += all * C;
	}
	cout << res << endl;
	return 0;
}