#include <cstdio>
#include <cstring>
#include <cassert>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <algorithm>
using namespace std;
typedef long long ll;

const int MAX_V = 100010;
const int MAX_LOG_V = 20;

int V;
vector<int> G[MAX_V];
int U[MAX_V];

int parent[MAX_LOG_V][MAX_V];
int sum[MAX_LOG_V][MAX_V];
int depth[MAX_V];

void dfs(int v, int p, int d){
	parent[0][v] = p;
	sum[0][v] = U[v];
	depth[v] = d;
	for(int u : G[v]){
		if(u != p){
			dfs(u, v, d + 1);
		}
	}
}

void init(){
	dfs(0, -1, 0);
	for(int k = 0; k + 1 < MAX_LOG_V; k++){
		for(int v = 0; v < V; v++){
			if(parent[k][v] < 0){
				parent[k + 1][v] = -1;
				sum[k + 1][v] = sum[k][v];
			} else {
				int p = parent[k][v];
				parent[k + 1][v] = parent[k][p];
				sum[k + 1][v] = sum[k][v] + sum[k][p];
			}
		}
	}
}

int solve(int u, int v){
	int res = 0;
	if(depth[u] > depth[v])swap(u, v);
	for(int k = 0; k < MAX_LOG_V; k++){
		if((depth[v] - depth[u]) >> k & 1){
			res += sum[k][v];
			v = parent[k][v];
		}
	}
	if(u == v){
		return res + U[u];
	}
	for(int k = MAX_LOG_V - 1; k >= 0; k--){
		if(parent[k][u] != parent[k][v]){
			res += sum[k][u] + sum[k][v];
			u = parent[k][u];
			v = parent[k][v];
		}
	}
	int lca = parent[0][u];
	res += U[u] + U[v] + U[lca];
	return res;
}

int main(){
	scanf("%d", &V);
	for(int i=0;i<V-1;i++){
		int v, u;
		scanf("%d %d", &v, &u);
		G[v].push_back(u);
		G[u].push_back(v);
	}
	for(int i=0;i<V;i++){
		scanf("%d", &U[i]);
	}
	init();

	int q;
	scanf("%d", &q);
	ll res = 0;
	for(int i=0;i<q;i++){
		int u, v, w;
		scanf("%d %d %d", &u, &v, &w);
		res += solve(u, v) * w;
	}

	printf("%lld\n", res);

	return 0;
}