#include <limits>
#include <iostream>
#include <algorithm>
#include <iomanip>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max() / 32 * 15 + 208;


template<class F>
struct SparseTable {
    using T = typename F::T;
    vector<vector<T>> table;
    vector<int> u;

    SparseTable() = default;

    explicit SparseTable(const vector<T> &v) { build(v); }

    void build(const vector<T> &v) {
        int n = v.size(), m = 1;
        while ((1 << m) <= n) m++;
        table.assign(m, vector<T>(n));
        u.assign(n + 1, 0);
        for (int i = 2; i <= n; ++i) {
            u[i] = u[i >> 1] + 1;
        }
        for (int i = 0; i < n; ++i) {
            table[0][i] = v[i];
        }
        for (int i = 1; i < m; ++i) {
            int x = (1 << (i - 1));
            for (int j = 0; j < n; ++j) {
                table[i][j] = F::f(table[i - 1][j], table[i - 1][min(j + x, n - 1)]);
            }
        }
    }

    T query(int a, int b) {
        int l = b - a;
        return F::f(table[u[l]][a], table[u[l]][b - (1 << u[l])]);
    }
};


struct F {
    using T = pair<int, int>;
    static T f(T a, T b) { return min(a, b); }
    static T e() { return T{INF<int>, -1}; }
};

class Graph {
    SparseTable<F> table;

    void dfs_euler(int v, int p, int d, int &k) {
        id[v] = k;
        vs[k] = v;
        depth[k++] = d;
        for (auto &&u : G[v]) {
            if (u != p) {
                dfs_euler(u, v, d + 1, k);
                vs[k] = v;
                depth[k++] = d;
            }
        }
    }

public:
    int n;
    vector<vector<int>> G;
    vector<int> vs, depth, id;

    explicit Graph(int n) : n(n), G(n), vs(2 * n - 1), depth(2 * n - 1), id(n), table() {};

    void add_edge(int a, int b) {
        G[a].emplace_back(b);
        G[b].emplace_back(a);
    }

    void eulertour(int root) {
        int k = 0;
        dfs_euler(root, -1, 0, k);
    }

    void buildLCA() {
        eulertour(0);
        vector<pair<int, int>> v(2 * n - 1);
        for (int i = 0; i < 2 * n - 1; ++i) {
            v[i] = make_pair(depth[i], i);
        }
        table.build(v);
    }

    int LCA(int u, int v) {
        if (id[u] > id[v]) swap(u, v);
        return vs[table.query(id[u], id[v] + 1).second];
    }
};

int main() {
    int n;
    cin >> n;
    Graph G(n);
    for (int i = 0; i < n - 1; ++i) {
        int a, b;
        scanf("%d %d", &a, &b);
        G.add_edge(a, b);
    }
    G.buildLCA();
    vector<int> dp(n);

    for (auto &&j : dp) scanf("%d", &j);
    auto val = dp;
    stack<int> s;
    vector<int> visited(n, 0);
    s.emplace(0);
    while(!s.empty()){
        int a = s.top(); s.pop();
        visited[a]++;
        for (auto &&i : G.G[a]) {
            if(!visited[i]) {
                s.emplace(i);
                dp[i] += dp[a];
            }
        }
    }
    int m;
    cin >> m;
    ll ans = 0;
    for (int i = 0; i < m; ++i) {
        int a, b, c;
        scanf("%d %d %d", &a, &b, &c);
        ans += c*(dp[a]+dp[b]-2*dp[G.LCA(a, b)]+val[G.LCA(a, b)]);
    }
    cout << ans << "\n";
    return 0;
}