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

class LCA {
public:
	LCA(int n) : g(n), parent(21, vector<int>(n, -1)), depth(n) {}

	void add(int u, int v) {
		g[u].push_back(v);
		g[v].push_back(u);
	}

	void build() {
		dfs(0, -1);
		for (int i = 0; i < 20; i++) {
			for (int j = 0; j < g.size(); j++) {
				if (parent[i][j] != -1) {
					parent[i + 1][j] = parent[i][parent[i][j]];
				}
			}
		}
	}

	int query(int u, int v) {
		if (depth[u] < depth[v]) swap(u, v);
		for (int i = 20; i >= 0; i--) {
			if (depth[u] - depth[v] >= 1 << i) {
				u = parent[i][u];
			}
		}
		if (u == v) return u;
		for (int i = 20; i >= 0; i--) {
			if (parent[i][u] != parent[i][v]) {
				u = parent[i][u];
				v = parent[i][v];
			}
		}
		return parent[0][u];
	}

private:
	vector<vector<int>> g, parent;
	vector<int> depth;

	void dfs(int curr, int prev) {
		parent[0][curr] = prev;
		for (int next : g[curr]) if (next != prev) {
			depth[next] = depth[curr] + 1;
			dfs(next, curr);
		}
	}
};

vector<int> g[101010];
long long cost[101010];
long long imos[101010];

void dfs(int curr, int prev) {
	for (int next : g[curr]) if (next != prev) {
		dfs(next, curr);
	}
	if (prev != -1) imos[prev] += imos[curr];
}

int main() {
	int n;
	cin >> n;

	LCA lca(n);
	for (int i = 0; i < n - 1; i++) {
		int u, v;
		scanf("%d %d", &u, &v);
		g[u].push_back(v);
		g[v].push_back(u);
		lca.add(u, v);
	}
	lca.build();

	for (int i = 0; i < n; i++) scanf("%lld", &cost[i]);

	long long ans = 0;

	int m;
	cin >> m;
	for (int i = 0; i < m; i++) {
		int a, b, c;
		scanf("%d %d %d", &a, &b, &c);

		int l = lca.query(a, b);
		ans += c * cost[l];
		imos[a] += c;
		imos[b] += c;
		imos[l] -= 2 * c;
	}

	dfs(0, -1);

	for (int i = 0; i < n; i++) {
		ans += cost[i] * imos[i];
	}
	cout << ans << endl;
}