#include<bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)n;i++)
#define all(c) (c).begin(),(c).end()
#define pb push_back
#define dbg(...) do{cerr<<__LINE__<<": ";dbgprint(#__VA_ARGS__, __VA_ARGS__);}while(0);

using namespace std;

namespace std{template<class S,class T>struct hash<pair<S,T>>{size_t operator()(const pair<S,T>&p)const{return ((size_t)1e9+7)*hash<S>()(p.first)+hash<T>()(p.second);}};template<class T>struct hash<vector<T>>{size_t operator()(const vector<T> &v)const{size_t h=0;for(auto i : v)h=h*((size_t)1e9+7)+hash<T>()(i)+1;return h;}};}
template<class T>ostream& operator<<(ostream &os, const vector<T> &v){os<<"[ ";rep(i,v.size())os<<v[i]<<(i==v.size()-1?" ]":", ");return os;}template<class T>ostream& operator<<(ostream &os,const set<T> &v){os<<"{ "; for(const auto &i:v)os<<i<<", ";return os<<"}";}
template<class T,class U>ostream& operator<<(ostream &os,const map<T,U> &v){os<<"{";for(const auto &i:v)os<<" "<<i.first<<": "<<i.second<<",";return os<<"}";}template<class T,class U>ostream& operator<<(ostream &os,const pair<T,U> &p){return os<<"("<<p.first<<", "<<p.second<<")";}
void dbgprint(const string &fmt){cerr<<endl;}template<class H,class... T>void dbgprint(const string &fmt,const H &h,const T&... r){cerr<<fmt.substr(0,fmt.find(","))<<"= "<<h<<" ";dbgprint(fmt.substr(fmt.find(",")+1),r...);}
typedef long long ll;typedef vector<int> vi;typedef pair<int,int> pi;const int inf = (int)1e9;const double INF = 1e12, EPS = 1e-9;

const int MX = 100010;
const int MX_L=17;

int n;
int parent[MX_L][MX];
int depth[MX], u[MX];
ll sum[MX];
vector<vi> e;

void dfs(int c, int p, int d){
	depth[c] = d;
	parent[0][c] = p;
	sum[c] = u[c] + sum[p];
	
	rep(i, e[c].size()){
		int to = e[c][i];
		if(to == p) continue;
		dfs(to, c, d + 1);
	}
}
inline int lca(int a, int b){
	if(depth[a] > depth[b]) swap(a, b);
	int d = depth[b] - depth[a];
	rep(i, MX_L) if(d & 1 << i) b = parent[i][b];
	if(a == b) return a;
	for(int i = MX_L - 1; i >= 0; i--) if(parent[i][a] != parent[i][b]){
		a = parent[i][a];
		b = parent[i][b];
	}
	return parent[0][a];
}

int main(){
	scanf("%d", &n);
	e.resize(n);
	rep(i, n - 1){
		int a, b; scanf("%d%d", &a, &b);
		e[a].pb(b);
		e[b].pb(a);
	}
	rep(i, n) scanf("%d", u + i);
	parent[0][n] = n;
	dfs(0, n, 1);
	rep(i, MX_L - 1) rep(j, n) parent[i + 1][j] = parent[i][parent[i][j]];
	
	int q;
	ll ans = 0;
	scanf("%d", &q);
	while(q--){
		int a, b, c;
		scanf("%d%d%d", &a, &b, &c);
		
		int x = lca(a, b);
		ll res = sum[a] + sum[b] - 2 * sum[x] + u[x];
		ans += (ll)c * res;
	}
	cout << ans << endl;
	
	return 0;
}