using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
class TEST{
	static void Main(){
		Sol mySol =new Sol();
		mySol.Solve();
	}
}

class Sol{
	public void Solve(){
		using(var r = new FastIn(100000)){
			N=r.ReadInt();
			E=new List<int>[N];
			for(int i=0;i<N;i++)E[i]=new List<int>();
			for(int i=0;i<N-1;i++){
				int[] d = new int[2];
				d[0] = r.ReadInt();
				d[1] = r.ReadInt();
				
				E[d[0]].Add(d[1]);
				E[d[1]].Add(d[0]);
			}
			U = new long[N];
			for(int i=0;i<N;i++){
				U[i] = r.ReadLong();
			}
			LCAInit();
			M =r.ReadInt();
			
			long[] sum = new long[N];
			for(int i=0;i<N;i++)sum[i] = U[i];
			Queue<int> Q = new Queue<int>();
			Q.Enqueue(root);
			
			while(Q.Count>0){
				var now = Q.Dequeue();
				foreach(var nxt in E[now]){
					if(nxt == parent[0][now])continue;
					sum[nxt] += sum[now];
					Q.Enqueue(nxt);
				}
			}
			
			long ans = 0;
			int from,to;
			long w;
			for(;M>0;M--){
				from = r.ReadInt();
				to = r.ReadInt();
				w = r.ReadLong();
				
				var p = lca(from,to);
				long weight = w * (sum[from] + sum[to] - 2*sum[p] + U[p]);
				ans += weight;
			}
			Console.WriteLine(ans);
		}
	}

	public Sol(){
	}
	
	int M;
	long[] U;
	int N;
	List<int>[] E;
	int[][] parent;
	int[] depth;
	static int lmax=24;
	int root;

	int lca(int u,int v){
		if(depth[u]>depth[v])return lca(v,u);
		for(int i=0;i<lmax;i++){
			if( (((depth[v]-depth[u])>>i)&1) >0 ){
				v=parent[i][v];
			}
		}
		if(u==v)return u;
		for(int i=lmax-1;i>=0;i--){
			if(parent[i][u]!=parent[i][v]){
				u=parent[i][u];
				v=parent[i][v];
			}
		}
		return parent[0][u];
	}
	
	void LCAInit(){
		parent=new int[lmax][];
		for(int i=0;i<lmax;i++){
			parent[i]=new int[N];
		}
		depth=new int[N];
		
		root=0;
		//dfs(root,-1,0);//深さを数えるdfs
		bfs(root,0);//深さを数えるbfs
		
		for(int i=0;i<lmax-1;i++){
			for(int j=0;j<N;j++){
				if(parent[i][j]<0){
					parent[i+1][j]=-1;
				}else{
					parent[i+1][j]=parent[i][parent[i][j]];
				}
			}
		}
		
	}
	
	void dfs(int now,int par,int dep){
		parent[0][now]=par;
		depth[now]=dep;
		foreach(int v in E[now]){
			if(v!=par){
				dfs(v,now,dep+1);
			}
		}
	}
	
	void bfs(int strt,int dep_strt){
		Queue<int> Q=new Queue<int>();
		parent[0][strt]=-1;depth[strt]=0;
		Q.Enqueue(strt);
		while(Q.Count>0){
			int now=Q.Dequeue();
			int par=parent[0][now];
			foreach(int v in E[now]){
				if(v!=par){
					parent[0][v]=now;depth[v]=depth[now]+1;
					Q.Enqueue(v);
				}
			}
		}
	}
	
	static String rs(){return Console.ReadLine();}
	static int ri(){return int.Parse(Console.ReadLine());}
	static long rl(){return long.Parse(Console.ReadLine());}
	static double rd(){return double.Parse(Console.ReadLine());}
	static String[] rsa(char sep=' '){return Console.ReadLine().Split(sep);}
	static int[] ria(char sep=' '){return Array.ConvertAll(Console.ReadLine().Split(sep),e=>int.Parse(e));}
	static long[] rla(char sep=' '){return Array.ConvertAll(Console.ReadLine().Split(sep),e=>long.Parse(e));}
	static double[] rda(char sep=' '){return Array.ConvertAll(Console.ReadLine().Split(sep),e=>double.Parse(e));}
}


class FastIn:IDisposable {
	int Size;
	byte[] Mem;
	int ptr;
	int rsize;
	bool unfinished;
	Stream stdin;
	void Init(int n) {
		Size = n;
		Mem = new byte[Size];
		rsize=(stdin=Console.OpenStandardInput()).Read(Mem, 0, Size);
		ptr = 0;
		unfinished=(rsize == Size);
	}
	void Next() {
		if (unfinished == false) return;
		rsize=stdin.Read(Mem, 0, Size);
		ptr = 0;
		unfinished = (rsize == Size);
	}
	
	~FastIn(){
		stdin.Dispose();
	}
	void IDisposable.Dispose(){
		stdin.Dispose();
	}
	public void Dispose(){
		stdin.Dispose();
	}
	
	public FastIn() {
		Init(100000);
	}
	public FastIn(int n) {
		Init(n);
	}
	public int ReadInt() {
		int ret = 0;
		int sig = 1;
		while (ptr < rsize && Mem[ptr] != ' ' && Mem[ptr] != '\n' && Mem[ptr] != '\r' ) {
			if(ret==0 && Mem[ptr] == '-'){
				sig *= -1; ptr++; continue;
			}
			ret = ret * 10 + Mem[ptr++] - '0';
			if (ptr == Size) Next();
		}
		while (ptr < rsize && (Mem[ptr] == ' ' || Mem[ptr] == '\n' || Mem[ptr] == '\r') ) {
			ptr++;
			if (ptr == Size) Next();
		}
		return ret*sig;
	}
	public long ReadLong() {
		long ret = 0;
		long sig = 1;
		while (ptr < rsize && Mem[ptr] != ' ' && Mem[ptr] != '\n' && Mem[ptr] != '\r' ) {
			if(ret==0 && Mem[ptr] == '-'){
				sig *= -1; ptr++; continue;
			}
			ret = ret * 10 + Mem[ptr++] - '0';
			if (ptr == Size) Next();
		}
		while (ptr < rsize &&  (Mem[ptr] == ' ' || Mem[ptr] == '\n' || Mem[ptr] == '\r')  ) {
			ptr++;
			if (ptr == Size) Next();
		}
		return ret*sig;
	}
	public String ReadStr() {
		//2byte文字はNG
		StringBuilder sb = new StringBuilder();
		while (ptr < rsize && Mem[ptr] != ' ' && Mem[ptr] != '\n' && Mem[ptr] != '\r') {
			sb.Append((char)Mem[ptr++]);
			if (ptr == Size && unfinished) Next();
		}
		while (ptr < rsize &&  (Mem[ptr] == ' ' || Mem[ptr] == '\n' || Mem[ptr] == '\r') ) {
			ptr++;
			if (ptr == Size && unfinished) Next();
		}
		return sb.ToString();
	}
	public String ReadLine() {
		//極力使わない(split/parseするくらいなら上をつかう）
		StringBuilder sb = new StringBuilder();
		while (ptr < rsize && Mem[ptr] != '\n' && Mem[ptr] != '\r') {
			sb.Append((char)Mem[ptr++]);
			if (ptr == Size && unfinished) Next();
		}
		while (ptr < rsize &&  (Mem[ptr] == ' ' || Mem[ptr] == '\n' || Mem[ptr] == '\r')) {
			ptr++;
			if (ptr == Size && unfinished) Next();
		}
		return sb.ToString();
	}
}