#include <bits/stdc++.h>
using namespace std;
#define all(c) (c).begin(),(c).end()
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define REP(i,m,n) for(int i=(int)(m);i<(int)(n);i++)
#define rep(i,n) REP(i,0,n)
#define iter(c) __typeof((c).begin())
#define tr(it,c) for(iter(c) it=(c).begin();it!=(c).end();it++)
#define mem(a) memset(a,0,sizeof(a))
#define pd(a) printf("%.10f\n",a)
#define pb(a) push_back(a)
#define in(a) insert(a)
#define pi M_PI
#define R cin>>
#define F first
#define S second
#define C class
#define ll long long
#define ln cout<<'\n'
template<C T>void pr(T a){cout<<a;ln;}
template<C T,C T2>void pr(T a,T2 b){cout<<a<<' '<<b;ln;}
template<C T,C T2,C T3>void pr(T a,T2 b,T3 c){cout<<a<<' '<<b<<' '<<c;ln;}
template<C T>void PR(T a,int n){rep(i,n){if(i)cout<<' ';cout<<a[i];}ln;}
bool check(int n,int m,int x,int y){return x>=0&&x<n&&y>=0&&y<m;}
const ll MAX=1000000007,MAXL=1LL<<60,dx[4]={-1,0,1,0},dy[4]={0,1,0,-1};
typedef pair<int,int> P;

ll d[100001],a[100001];
int dep[100010],p[100001];
int par[100010][19];
vector<int> g[100010];
void dfs(int v,int u,int d){
  dep[v]=d;
  p[v]=u;
  for(int i=0; i<g[v].size(); i++){
    int w=g[v][i];if(w==u) continue;
    par[w][0]=v;dfs(w,v,d+1);
  }
}
int lcp(int a,int b){
  if(dep[a]<dep[b]) swap(a,b);
  for(int i=0; i<19; i++){
    if(((dep[a]-dep[b])&(1<<i))) a=par[a][i];
  }
  if(a==b) return a;
  for(int i=18;i>=0;i--){
    if(par[a][i]!=par[b][i]) a=par[a][i],b=par[b][i];
  }
  return par[a][0];
}

ll dfs2(int x,int z) {
  ll sum=0;
  rep(i,g[x].size()) {
    int y=g[x][i];
    if(y==z) continue;
    sum+=dfs2(y,x);
    d[x]+=d[y];
  }
  return sum+a[x]*d[x];
}
void Main() {
  ll n;
  cin >> n;
  rep(i,n-1) {
    int x,y;
    cin >> x >> y;
    g[x].pb(y);
    g[y].pb(x);
  }
  memset(par,0,sizeof(par));
  dfs(0,-1,0);
  for(int i=0; i<18; i++) for(int j=0; j<n; j++) par[j][i+1]=par[par[j][i]][i];
  rep(i,n) cin >> a[i];
  int m;
  cin >> m;
  while(m--) {
    ll x,y,z;
    cin >> x >> y >> z;
    d[x]+=z;
    d[y]+=z;
    int l=lcp(x,y);
    d[l]-=z;
    if(l>=0) d[p[l]]-=z;
  }
  pr(dfs2(0,-1));
}

int main() {
  ios::sync_with_stdio(0);cin.tie(0);
  Main();return 0;
}