#include <iostream>
#include <vector>
using namespace std;

#define MAXN (100000+1)
#define MAXM (200000+1)

int N, M;
vector<int> tree[MAXN];
int cost[MAXN];
int cost_sum[MAXN];
int depth[MAXN];
int log_n;
vector<vector<int> > par;

void dfs(int v, int p, int c, int d)
{
    par[0][v] = p;
    depth[v] = d;
    cost_sum[v] = cost[v] + c;
    for (int i = 0; i < tree[v].size(); i++) {
        if (tree[v][i] != p) {
            dfs(tree[v][i], v, cost_sum[v], d+1);
        }
    }
}

void init()
{
    while (N > (1 << log_n)) log_n++;
    par = vector<vector<int> >(log_n, vector<int>(N));
    dfs(0, -1, 0, 0);
    for (int k = 0; k < log_n-1; k++) {
        for(int v = 0; v < N; v++) {
            if (par[k][v] < 0) {
                par[k+1][v] = -1;
            }
            else {
                par[k+1][v] = par[k][par[k][v]];
            }
        }
    }
}

int solve(int u, int v)
{
    if (depth[u] > depth[v]) {
        swap(u, v);
    }
    for (int k = 0; k < log_n; k++) {
        if((depth[v] - depth[u]) >> k & 1)v = par[k][v];
    }
    if(u==v)return u;

    for (int k = log_n-1; k >= 0; k--) {
        if (par[k][u] != par[k][v]) {
            u = par[k][u];
            v = par[k][v];
        }
    }
    return par[0][u];
}

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

    cin >> N;
    for (int n = 0; n < (N-1); n++) {
        int a, b;
        cin >> a;
        cin >> b;
        tree[a].push_back(b);
        tree[b].push_back(a);
    }
    for (int n = 0; n < N; n++) {
        cin >> cost[n];
    }
    init();

    unsigned long long total = 0;
    cin >> M;
    for (int m = 0; m < M; m++) {
        int a, b, c, p;
        cin >> a;
        cin >> b;
        cin >> c;
        p = solve(a, b);
        total += (cost_sum[a] + cost_sum[b] - (cost_sum[p] * 2) + cost[p]) * c;
    }
    cout << total << endl;
}