#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define vtpl(x,y,z) vector<tuple<x,y,z>>
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[9]={0,1,-1,0,1,1,-1,-1,0};
const ll dx[9]={1,0,0,-1,1,-1,1,-1,0};
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
} 

struct Edge {
    long long to;
};
using Graph = vector<vector<Edge>>;
struct LCA {
    vector<vector<int>> parent;  // parent[k][u]:= u の 2^k 先の親
    vector<int> dist;            // root からの距離
    LCA(const Graph &G, int root = 0) { init(G, root); }
    void init(const Graph &G, int root = 0) {
        int V = G.size();
        int K = 1;
        while ((1 << K) < V) K++;
        parent.assign(K, vector<int>(V, -1));
        dist.assign(V, -1);
        dfs(G, root, -1, 0);
        for (int k = 0; k + 1 < K; k++) {
            for (int v = 0; v < V; v++) {
                if (parent[k][v] >= 0) {
                    parent[k + 1][v] = parent[k][parent[k][v]];
                }
            }
        }
    }
    // 根からの距離と1つ先の頂点を求める
    void dfs(const Graph &G, int v, int p, int d) {
        parent[0][v] = p;
        dist[v] = d;
        for (auto e : G[v]) {
            if (e.to != p) {
                dfs(G, e.to, v, d + 1);
            }
        }
    }
    int query(int u, int v) {
        if (dist[u] < dist[v]) swap(u, v);  // u の方が深いとする
        int K = parent.size();
        // LCA までの距離を同じにする
        for (int k = 0; k < K; k++) {
            if ((dist[u] - dist[v])&(1<<k) ){
                u = parent[k][u];
            }
        }
        // 二分探索で LCA を求める
        if (u == v) return u;
        for (int k = K - 1; k >= 0; k--) {
            if (parent[k][u] != parent[k][v]) {
                u = parent[k][u];
                v = parent[k][v];
            }
        }
        return parent[0][u];
    }
    int length(int u, int v) { return dist[u] + dist[v] - 2 * dist[query(u, v)]; }
    bool is_in(int u, int v, int a) { return length(u, a) + length(a, v) == length(u, v); }
};

vector<vector<Edge>> g(100010);
vl dp(100010);
vl lc(100010);
ll dfs(ll v,ll par=-1){
    for(auto p:g[v]){
        if(p.to==par)continue;
        dp[v]+=dfs(p.to,v);
    }
    return dp[v]-lc[v]*2;
}
int main(){
    ll n;cin >> n;
    rep(i,n-1){
        ll a,b;cin >> a >> b;
        g[a].push_back({b});
        g[b].push_back({a});
    }
    LCA lca(g);
    vl x(n);rep(i,n)cin >> x[i];
    ll q;cin >> q;
    while(q--){
        ll a,b,c;cin >> a >> b >> c;
        ll l=lca.query(a,b);
        lc[l]+=c;
        dp[a]+=c;
        dp[b]+=c;
    }
    dfs(0);
    ll ans=0;
    rep(i,n){
        ans+=x[i]*(dp[i]-lc[i]);
    }
    cout << ans << endl;
}