#include <vector>
#include <iostream>
#include <climits>
#include <utility>
#include <cmath>
#include <cstring>
using namespace std;

typedef long long ll;

const int kMAX_N = 100010;
const int kMAX_M = 200010;
const int kMAX_V = kMAX_N;
const int kMAX_LOG_V = 20;

struct LCA {
    int V;
    int root;
    vector<int> graph[kMAX_V];
    int parent[kMAX_LOG_V][kMAX_V];
    int depth[kMAX_V];

    LCA() { }

    void init(int v, int r) {
        V = v;
        root = r;
        DFS(root, -1, 0);

        for (int k = 0; k + 1 < kMAX_LOG_V; k++) {
            for (int v = 0; v < V; v++) {
                if (parent[k][v] < 0) parent[k + 1][v] = -1;
                else parent[k + 1][v] = parent[k][parent[k][v]];
            }
        }
    }

    void AddEdge(int from, int to) {
        graph[from].push_back(to);
    }

    void DFS(int v, int p, int d) {
        parent[0][v] = p;
        depth[v] = d;
        for (int i = 0; i < graph[v].size(); i++) {
            if (graph[v][i] != p) DFS(graph[v][i], v, d + 1);
        }
    }

    int Solve(int u, int v) {
        if (depth[u] > depth[v]) swap(u, v);
        for (int k = 0; k < kMAX_LOG_V; k++) {
            if ((depth[v] - depth[u]) >> k & 1) {
                v = parent[k][v];
            }
        }
        if (u == v) return u;
        for (int k = kMAX_LOG_V - 1; k >= 0; k--) {
            if (parent[k][u] != parent[k][v]) {
                u = parent[k][u];
                v = parent[k][v];
            }
        }
        return parent[0][u];
    }
};


int N, M;
LCA lca;

int U[kMAX_N], cost[kMAX_N];

void DFS(int node, int par, int c) {
    cost[node] = c;
    for (int i = 0; i < lca.graph[node].size(); i++) {
        int to = lca.graph[node][i];
        if (to != par && cost[to] < 0) {
            DFS(to, node, c + U[to]);
        }
    }
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    cin >> N;

    for (int i = 0; i < N - 1; i++) {
        int a, b;
        cin >> a >> b;
        lca.AddEdge(a, b);
        lca.AddEdge(b, a);
    }
    for (int i = 0; i < N; i++) {
        cin >> U[i];
    }
    lca.init(N, 0);

    memset(cost, -1, sizeof(cost));
    DFS(0, -1, U[0]);

    ll answer = 0;
    cin >> M;
    for (int i = 0; i < M; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        int l = lca.Solve(a, b);
        ll road_cost = (ll)cost[a] + (ll)cost[b] - 2 * (ll)cost[l] + (ll)U[l];
        answer += road_cost * c;
    }
    cout << answer << endl;

    return 0;
}