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

class heavy_light_decomposition {
	const int n;
	vector<vector<int>> g;
	vector<int> in, out, size, head, par, dep, inv;
	int it;
	void erase_par(int v, int prev) {
		par[v] = prev;
		for (auto& u : g[v]) {
			if (u == g[v].back()) break;
			if (u == prev) swap(u, g[v].back());
			erase_par(u, v);
		}
		g[v].pop_back();
	}
	void dfs1(int v) {
		for (auto& u : g[v]) {
			dfs1(u);
			size[v] += size[u];
			if (size[u] > size[g[v][0]]) swap(u, g[v][0]);
		}
	}
	void dfs2(int v) {
		in[v] = it++;
		inv[in[v]] = v;
		for (auto u : g[v]) {
			head[u] = (u == g[v][0] ? head[v] : u);
			dep[u] = dep[v] + (u != g[v][0]);
			dfs2(u);
		}
		out[v] = it;
	}
public:
	heavy_light_decomposition(int n_)
		: n(n_), g(n), in(n, -1), out(n, -1), size(n, 1), head(n), par(n, -1), dep(n), inv(n), it(0) {}
	heavy_light_decomposition(const vector<vector<int>>& G)
		: n(G.size()), g(G), in(n, -1), out(n, -1), size(n, 1), head(n), par(n, -1), dep(n), inv(n), it(0) {}
	void add_edge(int u, int v) {
		g[u].push_back(v);
		g[v].push_back(u);
	}
	void build(int rt = 0) {
		for (auto v : g[rt]) erase_par(v, rt);
		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]];
		}
	}
	void subtree_query(int v, function<void(int, int)> f) {
		f(in[v], out[v]);
	}
	int get_lca(int u, int v) {
		while (true) {
			if (in[u] > in[v]) swap(u, v);
			if (head[u] == head[v]) return u;
			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;
}