#include<bits/stdc++.h>
#define rep(i,n)for(int i=0;i<(n);i++)
using namespace std;
typedef long long ll;

vector<int>E[100000];
int par[18][100000],depth[100000],u[100000];
ll sum[100000];

void dfs(int v,int p,int d){
	if(p==-1)sum[v]=u[v];
	else sum[v]=sum[p]+u[v];
	par[0][v]=p;depth[v]=d;
	for(int u:E[v]){
		if(u!=p)dfs(u,v,d+1);
	}
}
int lca(int u,int v){
	if(depth[u]>depth[v])swap(u,v);
	rep(i,18){
		if((depth[v]-depth[u])>>i&1)v=par[i][v];
	}
	if(u==v)return u;
	for(int i=17;i>=0;i--){
		if(par[i][u]!=par[i][v]){
			u=par[i][u];
			v=par[i][v];
		}
	}
	return par[0][u];
}
int main(){
	int n;scanf("%d",&n);
	rep(i,n-1){
		int a,b;scanf("%d%d",&a,&b);
		E[a].push_back(b);E[b].push_back(a);
	}
	rep(i,n)scanf("%d",&u[i]);
	dfs(0,-1,0);
	for(int i=1;i<18;i++)rep(j,n){
		if(par[i-1][j]==-1)par[i][j]=-1;
		else par[i][j]=par[i-1][par[i-1][j]];
	}
	int m;scanf("%d",&m);
	ll ans=0;
	rep(i,m){
		int a,b,c;scanf("%d%d%d",&a,&b,&c);
		int p=lca(a,b);
		ans+=(sum[a]+sum[b]-(par[0][p]==-1?0:sum[par[0][p]])-sum[p])*c;
	}
	printf("%lld\n",ans);
}