#ifdef LOCAL111
#else
	#define NDEBUG
#endif
#include <bits/stdc++.h>
const int INF = 1e8;
using namespace std;

#define endl '\n'
#define ALL(a)  (a).begin(),(a).end()
#define SZ(a) int((a).size())
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n)  FOR(i,0,n)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
#define RBP(i,a) for(auto& i : a)
#ifdef LOCAL111
	#define DEBUG(x) cout<<#x<<": "<<(x)<<endl
#else
	#define DEBUG(x) true
#endif
#define F first
#define S second
#define SNP string::npos
#define WRC(hoge) cout << "Case #" << (hoge)+1 << ": "
#define rangej(a,b,c) ((a) <= (c) and (c) < (b))
#define rrangej(b,c) rangej(0,b,c)
template<typename T> void pite(T a, T b){ for(T ite = a; ite != b; ite++) cout << (ite == a ? "" : " ") << *ite; cout << endl;}
template<typename T> bool chmax(T& a, T b){if(a < b){a = b; return true;} return false;}
template<typename T> bool chmin(T& a, T b){if(a > b){a = b; return true;} return false;}

typedef pair<int,int> P;
typedef long long int LL;
typedef unsigned long long ULL;
typedef pair<LL,LL> LP;

void ios_init(){
	//cout.setf(ios::fixed);
	//cout.precision(12);
#ifdef LOCAL111
	return;
#endif
	ios::sync_with_stdio(false); cin.tie(0);	
}

//library
typedef long long cost_t;

class Edge {
public:
	int to;
	cost_t cost;
	
	Edge(){
	}

	Edge(int x,cost_t y){
		to = x;
		cost = y;
	}

	bool operator< (const Edge& x) const {
		return cost < x.cost;
	}

	bool operator> (const Edge& x) const {
		return cost > x.cost;
	}
};

class Graph {
private:
	//const long long int INF = (long long)1e18;
	vector<vector<Edge> > v; 
	int n;
public:
	Graph(int x){
		n = x;
		v = vector<vector<Edge> >(x);
	}

	vector<Edge>& operator[](int x){
		return v[x];
	}

	const vector<Edge>& operator[](int x) const {
		return v[x];
	}

	int size() const {
		return n;
	}

	void add_edge(int from, Edge e){
		v[from].push_back(e);
	}

	void add_edge(int from, int to, cost_t cost){
		add_edge(from,Edge(to,cost));
	}

	void add_uedge(int from, int to, cost_t cost){
		add_edge(from,to,cost);
		add_edge(to,from,cost);
	}
};

vector<cost_t> dijkstra(int from, const Graph& v) {
	vector<cost_t> dist(v.size(),INF);
	priority_queue<Edge,vector<Edge>,greater<Edge>> que;
	que.push(Edge(from,0));
	while(!que.empty()){
		Edge e = que.top();
		que.pop();
		if(dist[e.to] == INF){
			dist[e.to] = e.cost;
			for(auto to : v[e.to]){
				if(dist[to.to] == INF)
					que.push(Edge(to.to, e.cost+to.cost));
			}
		}
	}
	return dist;
}

vector<cost_t> bellmanford(int from, const Graph& g){
	vector<cost_t> res(g.size(),INF);
	res[from] = 0;
	bool conf = true;
	int cnt = 0;
	while(conf){
		conf = false;
		for(int i = 0; i < g.size(); i++){
			if(res[i] != INF)
			for(const auto& e : g[i]){
				if(res[e.to] > res[i]+e.cost){
					conf = true;
					res[e.to] = res[i]+e.cost;
				}
			}
		}
		if(cnt > g.size()+5) return vector<cost_t>();
		cnt++;
	}
	return res;
}

Graph prim(const Graph g){
	using T = tuple<cost_t, int, int>;
	priority_queue<T, vector<T>, greater<T>> qu;
	int n = g.size();
	assert(n != 0);
	vector<bool> added(n,false);
	qu.emplace(0,0,0);
	Graph res(n);
	while(!qu.empty()){
		int from, to;
		cost_t cost;
		tie(cost, from, to) = qu.top();
		qu.pop();
		if(!added[to]){
			added[to] = true;
			res.add_edge(from, to, cost);
			res.add_edge(to, from, cost);
			for(const auto &e : g[to]){
				if(!added[e.to]){
					qu.emplace(e.cost, to, e.to);
				}
			}
		}
	}
	return res;
}

vector<int> tree_getorder(const Graph &g, int root){
	vector<int> res;
	function<void(int p, int pre)> func = [&](int p, int pre){
		for(auto &e : g[p]){
			if(e.to != pre){
				func(e.to,p);
			}
		}
		res.push_back(p);
	};
	func(root,-1);
	return res;
}

vector<int> tree_getpar(const Graph &g, int root){
	vector<int> par(g.size(),root);
	function<void(int p, int pre)> func = [&](int p, int pre){
		par[p] = pre;
		for(auto &e : g[p]){
			if(e.to != pre){
				func(e.to,p);
			}
		}
	};
	func(root,root);
	return par;
}

vector<cost_t> tree_imos(const Graph &g, int root){
	int n = g.size();
	vector<cost_t> res(n,0);
	function<void(int,int,cost_t)> dfs = [&](int p, int pre, cost_t sum){
		res[p] = sum;
		for(auto &e : g[p]){
			if(e.to != pre){
				dfs(e.to, p, sum+e.cost);
			}
		}
	};
	dfs(root, root,0);
	return res;
}
//liblary

//library
class LCA{
public:
	vector<vector<int>> parent;
	vector<int> depth;
	int maxlogv;
	LCA(const Graph &g, int root){
		int n = g.size();
		maxlogv = 0;
		int n_ = n;
		while(n_ != 0){
			n_ >>= 1;
			maxlogv++;
		}
		if((1<<maxlogv) < n) maxlogv++;
		parent = vector<vector<int>>(maxlogv,vector<int>(n,-1));
		depth = vector<int>(n,0);
		function<void(int,int,int)> dfs = [&](int v, int p, int d){
			parent[0][v] = p;
			depth[v] = d;
			for(const auto &e : g[v]){
				if(e.to != p) dfs(e.to, v, d+1);
			}
		};
		dfs(root,-1,0);
		for(int k = 0; k+1 < maxlogv; k++){
			for(int v = 0; v < n; v++){
				if(parent[k][v] < 0) parent[k+1][v] = -1;
				else parent[k+1][v] = parent[k][parent[k][v]];
			}
		}
	}

	cost_t query(int u, int v){
		if(depth[u] > depth[v]) swap(u,v);
		for(int k = 0; k < maxlogv; k++){
			if((depth[v]-depth[u]) >> k & 1){
				v = parent[k][v];
			}
		}
		if(u == v) return u;
		for(int k = maxlogv-1; k >= 0; k--){
			if(parent[k][u] != parent[k][v]){
				u = parent[k][u];
				v = parent[k][v];
			}
		}
		return parent[0][u];
	}
};
//library

int main()
{
	ios_init();
	int n;
	cin >> n;
	Graph g(n);
	REP(i,n-1){
		int a,b;
		cin >> a >> b;
		g.add_edge(a,b,-1);
		g.add_edge(b,a,-1);
	}
	vector<int> u(n);
	REP(i,n) cin >> u[i];
	auto pars = tree_getpar(g,0);
	REP(i,n){
		RBP(e,g[i]){
			if(pars[i] == e.to){
				e.cost = u[i];
			}else{
				e.cost = u[e.to];
			}
		}
	}
	LCA lca(g,0);
	auto imos = tree_imos(g,0);
	int m;
	cin >> m;
	LL ans = 0;
	REP(i,m){
		int a,b,c;
		cin >> a >> b >> c;
		auto x = lca.query(a,b);
		ans += (imos[a]+imos[b]-2*imos[x]+u[x])*c;
	}
	cout << ans << endl;
	return 0;
}