#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <algorithm>
#include <utility>
#include <functional>
#include <cstring>
#include <queue>
#include <stack>
#include <math.h>
#include <iterator>
#include <vector>
#include <string>
#include <set>
#include <math.h>
#include <iostream> 
#include<map>
#include <stdlib.h>
#include <list>
#include <typeinfo>
#include <list>
#include <set>
#include <iomanip>
using namespace std;
#define MAX_MOD 1000000007
#define REP(i,n) for(int i = 0;i < n;++i)
vector<int> sectors_first[200001];
vector<int> sectors_cal[200001];
int kazu[200001] = {};
long long score[200001] = {};
int main() {
	int n;
	cin >> n;
	for (int i = 0;i < n-1;++i) {
		int a, b;
		scanf("%d%d",&a,&b);
		sectors_first[a].push_back(b);
		sectors_first[b].push_back(a);
	}
	for (int i = 0;i < n;++i) {
		scanf("%d", &kazu[i]);
	}
	score[150000] = 1;
	score[0] = kazu[0]+1;//1＋
	queue<int> next_go;
	next_go.push(0);
	while (next_go.empty() == false) {
		int hoge = next_go.front();
		next_go.pop();
		for (int q = 0;q < sectors_first[hoge].size();++q) {
			if (score[sectors_first[hoge][q]] == 0) {
				sectors_cal[sectors_first[hoge][q]].push_back(hoge);
				score[sectors_first[hoge][q]] = kazu[sectors_first[hoge][q]] + score[hoge];
				next_go.push(sectors_first[hoge][q]);
			}
		}
	}
	sectors_cal[0].push_back(150000);
	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);
		long long pre_ans = score[a] + score[b] - 2;
		bool ok[200000] = {};
		queue<int> hogee;
		hogee.push(a);
		hogee.push(b);
		while (hogee.empty() == false) {
			int wow = hogee.front();hogee.pop();
			if (ok[wow] == false) {
				ok[wow] = true;
				if (wow != 0) {
					hogee.push(sectors_cal[wow][0]);
				}
			}else{
				pre_ans -= score[wow] - 1+score[sectors_cal[wow][0]]-1;
				goto ok;
			}
		}
	ok:;
		ans += pre_ans * c;
	}
	cout << ans << endl;
}