import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.Closeable;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.BitSet;
import java.util.HashMap;
import java.util.List;
import java.util.Random;
import java.util.TreeMap;

public class Main {
	static ContestScanner in;static Writer out;public static void main(String[] args)
	{try{in=new ContestScanner();out=new Writer();Main solve=new Main();solve.solve();
	in.close();out.flush();out.close();}catch(IOException e){e.printStackTrace();}}
	static void dump(int[]a){for(int i=0;i<a.length;i++)out.print(a[i]+" ");out.println();}
	static void dump(int[]a,int n){for(int i=0;i<a.length;i++)out.printf("%"+n+"d ",a[i]);out.println();}
	static void dump(long[]a){for(int i=0;i<a.length;i++)out.print(a[i]+" ");out.println();}
	static void dump(char[]a){for(int i=0;i<a.length;i++)out.print(a[i]);out.println();}
	static long pow(long a,int n){long r=1;while(n>0){if((n&1)==1)r*=a;a*=a;n>>=1;}return r;}
	static String itob(int a,int l){return String.format("%"+l+"s",Integer.toBinaryString(a)).replace(' ','0');}
	static void sort(int[]a){m_sort(a,0,a.length,new int[a.length]);}
	static void sort(int[]a,int l){m_sort(a,0,l,new int[l]);}
	static void sort(int[]a,int l,int[]buf){m_sort(a,0,l,buf);}
	static void sort(int[]a,int s,int l,int[]buf){m_sort(a,s,l,buf);}
	static void m_sort(int[]a,int s,int sz,int[]b)
	{if(sz<7){for(int i=s;i<s+sz;i++)for(int j=i;j>s&&a[j-1]>a[j];j--)swap(a, j, j-1);return;}
	m_sort(a,s,sz/2,b);m_sort(a,s+sz/2,sz-sz/2,b);int idx=s;int l=s,r=s+sz/2;final int le=s+sz/2,re=s+sz;
	while(l<le&&r<re){if(a[l]>a[r])b[idx++]=a[r++];else b[idx++]=a[l++];}
	while(r<re)b[idx++]=a[r++];while(l<le)b[idx++]=a[l++];for(int i=s;i<s+sz;i++)a[i]=b[i];
	} /* qsort(3.5s)<<msort(9.5s)<<<shuffle+qsort(17s)<Arrays.sort(Integer)(20s) */
	static void sort(long[]a){m_sort(a,0,a.length,new long[a.length]);}
	static void sort(long[]a,int l){m_sort(a,0,l,new long[l]);}
	static void sort(long[]a,int l,long[]buf){m_sort(a,0,l,buf);}
	static void sort(long[]a,int s,int l,long[]buf){m_sort(a,s,l,buf);}
	static void m_sort(long[]a,int s,int sz,long[]b)
	{if(sz<7){for(int i=s;i<s+sz;i++)for(int j=i;j>s&&a[j-1]>a[j];j--)swap(a, j, j-1);return;}
	m_sort(a,s,sz/2,b);m_sort(a,s+sz/2,sz-sz/2,b);int idx=s;int l=s,r=s+sz/2;final int le=s+sz/2,re=s+sz;
	while(l<le&&r<re){if(a[l]>a[r])b[idx++]=a[r++];else b[idx++]=a[l++];}
	while(r<re)b[idx++]=a[r++];while(l<le)b[idx++]=a[l++];for(int i=s;i<s+sz;i++)a[i]=b[i];}
	static void swap(long[] a,int i,int j){final long t=a[i];a[i]=a[j];a[j]=t;}
	static void swap(int[] a,int i,int j){final int t=a[i];a[i]=a[j];a[j]=t;}
	static int binarySearchSmallerMax(int[]a,int v)// get maximum index which a[idx]<=v
	{int l=-1,r=a.length-1,s=0;while(l<=r){int m=(l+r)/2;if(a[m]>v)r=m-1;else{l=m+1;s=m;}}return s;}
	static int binarySearchSmallerMax(int[]a,int v,int l,int r)
	{int s=-1;while(l<=r){int m=(l+r)/2;if(a[m]>v)r=m-1;else{l=m+1;s=m;}}return s;}
	void solve() throws NumberFormatException, IOException{
		int n = in.nextInt();
		tree = new List[n];
		for(int i=0; i<n; i++) tree[i] = new ArrayList<>();
		for(int i=0; i<n-1; i++){
			int a = in.nextInt();
			int b = in.nextInt();
			tree[a].add(b);
			tree[b].add(a);
		}
		int m = n;
		while(m>0){
			log++;
			m >>= 1;
		}
		parent = new int[n][log+1];
		dep = new int[n];
		checkParNonRec(0, n);
		for(int i=1; i<=log; i++){
			for(int j=0; j<n; j++){
				parent[j][i] = parent[parent[j][i-1]][i-1];
			}
		}
		cost = new int[n];
		for(int i=0; i<n; i++){
			cost[i] = in.nextInt();
		}
		sum = new int[n];
		nonRec(0);
		m = in.nextInt();
		long ans = 0;
		for(int i=0; i<m; i++){
			int a = in.nextInt();
			int b = in.nextInt();
			int c = in.nextInt();
			int lca = lca(a, b);
			ans += ((long)sum[a]+sum[b]-sum[lca]*2+cost[lca])*c;
		}
		System.out.println(ans);
	}
	
	void dfs(int cur, int par, int c){
		sum[cur] = c+cost[cur];
		for(int v: tree[cur]){
			if(v==par) continue;
			dfs(v, cur, sum[cur]);
		}
	}
	void nonRec(int root){
		sp = 1;
		stc[0] = 0;
		stp[0] = 0;
		std[0] = 0;
		while(sp>0){
			final int cur = stc[--sp];
			final int par = stp[sp];
			final int s = std[sp];
			sum[cur] = s+cost[cur];
			for(int v: tree[cur]){
				if(v==par) continue;
				stc[sp] = v;
				stp[sp] = cur;
				std[sp] = sum[cur];
				sp++;
			}
		}
	}
	int[] sum;
	int[] cost;
	
	List<Integer>[] tree;
	int[][] parent;
	int[] dep;
	int log;
	void checkPar(int cur, int par, int d){
		dep[cur] = d;
		parent[cur][0] = par;
		for(int v: tree[cur]){
			if(v==par) continue;
			checkPar(v, cur, d+1);
		}
	}
	int[] stc, stp, std;
	int sp;
	void checkParNonRec(int root, int n){
		stc = new int[n];
		stp = new int[n];
		std = new int[n];
		sp = 1;
		while(sp>0){
			final int cur = stc[--sp];
			final int par = stp[sp];
			final int d = std[sp];
			dep[cur] = d;
			parent[cur][0] = par;
			for(int v: tree[cur]){
				if(v==par) continue;
				stc[sp] = v;
				stp[sp] = cur;
				std[sp] = d+1;
				sp++;
			}
		}
	}
	int lca(int u, int v){
		// dep[u] <= dep[v]
		if(dep[u]>dep[v]){
			final int tmp = u; u = v; v = tmp;
		}
		for(int i=0, d=dep[v]-dep[u]; d>0; i++, d>>=1){
			if((d&1)==1) v = parent[v][i];
		}
		if(u==v) return u;
		for(int i=log-1; i>=0; i--){
			if(parent[v][i]!=parent[u][i]){
				v = parent[v][i];
				u = parent[u][i];
			}
		}
		return parent[u][0];
	}
}

 
class MultiSet<T> extends HashMap<T, Integer>{
	@Override public Integer get(Object key){return containsKey(key)?super.get(key):0;}
	public void add(T key,int v){put(key,get(key)+v);}
	public void add(T key){put(key,get(key)+1);}
	public void sub(T key){final int v=get(key);if(v==1)remove(key);else put(key,v-1);}
	public MultiSet<T> merge(MultiSet<T> set)
	{MultiSet<T>s,l;if(this.size()<set.size()){s=this;l=set;}else{s=set;l=this;}
	for(Entry<T,Integer>e:s.entrySet())l.add(e.getKey(),e.getValue());return l;}
}
class OrderedMultiSet<T> extends TreeMap<T, Integer>{
	@Override public Integer get(Object key){return containsKey(key)?super.get(key):0;}
	public void add(T key,int v){put(key,get(key)+v);}
	public void add(T key){put(key,get(key)+1);}
	public void sub(T key){final int v=get(key);if(v==1)remove(key);else put(key,v-1);}
	public OrderedMultiSet<T> merge(OrderedMultiSet<T> set)
	{OrderedMultiSet<T>s,l;if(this.size()<set.size()){s=this;l=set;}else{s=set;l=this;}
	while(!s.isEmpty()){l.add(s.firstEntry().getKey(),s.pollFirstEntry().getValue());}return l;}
}
class Pair implements Comparable<Pair>{
	int a,b;final int hash;Pair(int a,int b){this.a=a;this.b=b;hash=(a<<16|a>>16)^b;}
	public boolean equals(Object obj){Pair o=(Pair)(obj);return a==o.a&&b==o.b;}
	public int hashCode(){return hash;}
	public int compareTo(Pair o){if(a!=o.a)return a<o.a?-1:1;else if(b!=o.b)return b<o.b?-1:1;return 0;}
}
class Timer{
	long time;public void set(){time=System.currentTimeMillis();}
	public long stop(){return time=System.currentTimeMillis()-time;}
	public void print(){System.out.println("Time: "+(System.currentTimeMillis()-time)+"ms");}
	@Override public String toString(){return"Time: "+time+"ms";}
}
class Writer extends PrintWriter{
	public Writer(String filename)throws IOException
	{super(new BufferedWriter(new FileWriter(filename)));}
	public Writer()throws IOException{super(System.out);}
}
class ContestScanner implements Closeable{
	private BufferedReader in;private int c=-2;
	public ContestScanner()throws IOException 
	{in=new BufferedReader(new InputStreamReader(System.in));}
	public ContestScanner(String filename)throws IOException
	{in=new BufferedReader(new InputStreamReader(new FileInputStream(filename)));}
	public String nextToken()throws IOException {
		StringBuilder sb=new StringBuilder();
		while((c=in.read())!=-1&&Character.isWhitespace(c));
		while(c!=-1&&!Character.isWhitespace(c)){sb.append((char)c);c=in.read();}
		return sb.toString();
	}
	public String readLine()throws IOException{
		StringBuilder sb=new StringBuilder();if(c==-2)c=in.read();
		while(c!=-1&&c!='\n'&&c!='\r'){sb.append((char)c);c=in.read();}
		return sb.toString();
	}
	public long nextLong()throws IOException,NumberFormatException
	{return Long.parseLong(nextToken());}
	public int nextInt()throws NumberFormatException,IOException
	{return(int)nextLong();}
	public double nextDouble()throws NumberFormatException,IOException 
	{return Double.parseDouble(nextToken());}
	public void close() throws IOException {in.close();}
}