#include <bits/stdc++.h>
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define FORR(i,a,b) for (int i=(a);i>=(b);i--)
#define pb push_back
#define pcnt __builtin_popcount
#define show(x) cout<<#x<<" = "<<x<<endl;
#define maxs(x,y) x = max(x,y)
#define mins(x,y) x = min(x,y)
#define fi first
#define se second
#define rng(a) a.begin(),a.end()
#define each(it,c) for(__typeof((c).begin()) it=(c).begin();it!=(c).end();it++)
#define sz(x) (int)(x).size()
#define mp make_pair

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pii> vpii;
typedef set<int> si;
typedef pair<ll,ll> pll;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<pll> vpll;
typedef set<ll> sl;
template<typename T>string join(vector<T>&v)
{stringstream s;FOR(i,0,sz(v))s<<' '<<v[i];return s.str().substr(1);}
ll gcd(ll a,ll b){if(a>b)swap(a,b);for(;a>0;b%=a,swap(a,b));return b;}
int modpow(ll a,ll n,int m){if(a==0)return a;ll p=1;for(;n>0;n/=2,a=a*a%m)if(n&1)p=p*a%m;return(int)p;}
void dout(double d){printf("%.12f\n",d);}

const int iinf = 1e9;
const ll linf = 1e18;
const int mod = 1e9+7;
const double pi = acos(-1);
const double eps = 1e-10;
const int N = 100005;

int n, p[N][17], d[N], u[N], su[N];
queue<int> q, q2;
vi m[N];
bool B[N];

int root(int d1, int d2){
  FORR(i, 16, 0)if(p[d1][i] != p[d2][i]) return root(p[d1][i], p[d2][i]);
  return p[d1][0];
}
main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  cin >> n;
  int a, b, c;
  FOR(i, 0, n-1){
    cin >> a >> b;
    m[a].pb(b);
    m[b].pb(a);
  }
  FOR(i, 0, n) cin >> u[i];
  a = 0;
  q.push(0);
  B[0] = true;
  su[0] = u[0];
  while(!q.empty()){
    a++;
    while(!q.empty()){
      b = q.front();
      q.pop();
      each(itr, m[b]){
        if(B[*itr]) continue;
        B[*itr] = true;
        p[*itr][0] = b;
        d[*itr] = a;
        su[*itr] = su[b] + u[*itr];
        q2.push(*itr);
      }
    }
    swap(q, q2);
  }
  FOR(i, 1, 17)FOR(j, 0, n) p[j][i] = p[p[j][i-1]][i-1];
  ll ans = 0;
  int M;
  cin >> M;
  FOR(i, 0, M){
    cin >> a >> b >> c;
    if(d[a] > d[b]) swap(a, b);
    int w = d[b] - d[a], x = b;
    FORR(j, 16, 0)if((1<<j) & w) x = p[x][j];
    int r = (a == x ? a : root(a, x));
    ans += (su[a] + su[b] - su[r]*2 + u[r]) * c;
  }
  cout << ans << endl;
  return 0;
}