#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define pb push_back
#define ppb pop_back
#define fr first
#define sc second
#define all(v) v.begin(), v.end()
#define vektor vector
using namespace std;
using namespace __gnu_pbds;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
constexpr ull Mod = 1e9 + 7;
constexpr ull sqr = 223;
constexpr ld eps = 1e-9;
constexpr int N = 1e5;
int n;
ll st[4 * N + 5];
void update111(int idx, int l, int r, int i, ll val){
if(l == r){
st[idx] = val;
return;
}
int mid = (l + r) >> 1;
if(i <= mid) update111(idx << 1, l, mid, i, val);
else update111(idx << 1 | 1, mid + 1, r, i, val);
st[idx] = st[idx << 1] + st[idx << 1 | 1];
}
ll query111(int idx, int l, int r, int u, int v){
if(v < l || r < u) return 0;
if(u <= l && r <= v) return st[idx];
int mid = (l + r) >> 1;
return query111(idx << 1, l, mid, u, v) + query111(idx << 1 | 1, mid + 1, r, u, v);
}
void update(int i, ll val){ update111(1, 1, N, i, val); }
ll query(int l, int r){ return query111(1, 1, N, l, r); }
vector <int> graph[N + 5];
int h[N + 5], subtr[N + 5], p[N + 5][25];
int heavy_p[N + 5];
int id[N + 5];
int lca(int u, int v){
if(h[u] < h[v]) swap(u, v);
int diff = h[u] - h[v];
for(int i = 20; i >= 0; i--){
if(diff & (1 << i)){
u = p[u][i];
}
}
if(u == v) return u;
for(int i = 20; i >= 0; i--){
if(p[u][i] != p[v][i]){
u = p[u][i];
v = p[v][i];
}
}
return p[u][0];
}
void dfs111(int node, int pr){
h[node] = h[pr] + 1;
subtr[node] = 1;
p[node][0] = pr;
for(int i = 1; i <= 20; i++){
p[node][i] = p[p[node][i-1]][i-1];
}
for(auto& x : graph[node]){
if(x == pr) continue;
dfs111(x, node);
subtr[node] += subtr[x];
}
}
int timer = 0;
void dfs222(int node, int pr){
id[node] = ++ timer;
pair <int, int> mx = {0, 0};
for(auto& x : graph[node]){
if(x == pr) continue;
mx = max(mx, {subtr[x], x});
}
if(mx.fr){
heavy_p[mx.sc] = heavy_p[node];
dfs222(mx.sc, node);
}
for(auto& x : graph[node]){
if(x == mx.sc || x == pr) continue;
heavy_p[x] = x;
dfs222(x, node);
}
}
void preprocess(){
memset(st, 0, sizeof(st));
for(int i = 0; i <= n; ++i) for(int j = 0; j < 25; ++j) p[i][j] = 0;
heavy_p[1] = 1;
dfs111(1, 0);
dfs222(1, 0);
}
void update1(int u, ll val){
update(id[u], val);
}
ll query_subpath_excluding_anc(int u, int anc){
ll ans = 0;
while(heavy_p[u] != heavy_p[anc]){
ans += query(id[heavy_p[u]], id[u]);
u = p[heavy_p[u]][0];
}
if(id[anc] + 1 <= id[u]) ans += query(id[anc] + 1, id[u]);
return ans;
}
ll query1(int u, int v){
if(h[u] < h[v]) swap(u, v);
int pr = lca(u, v);
ll ans = 0;
ans += query_subpath_excluding_anc(u, pr);
ans += query_subpath_excluding_anc(v, pr);
return ans;
}
struct eded{
int fr, sc;
ll val;
};
vector <eded> ed[N + 1];
ll base[N + 1], dp[N + 1];
void dfs(int node, int pr){
base[node] = 0;
for(auto& x : graph[node]) if(x != pr){
dfs(x, node);
base[node] += dp[x];
}
ll mx = 0;
for(auto& w : ed[node]){
ll s = query1(w.fr, w.sc);
ll cand = w.val - s;
if(cand > mx) mx = cand;
}
if(mx < 0) mx = 0;
dp[node] = base[node] + mx;
update1(node, mx);
}
void solve(){
cin >> n;
for(int i = 1; i < n; i ++){
int u, v;
cin >> u >> v;
graph[u].pb(v);
graph[v].pb(u);
}
preprocess();
int m;
cin >> m;
for(int i = 1; i <= m; i ++){
int u, v;
ll val;
cin >> u >> v >> val;
int pr = lca(u, v);
ed[pr].pb({u, v, val});
}
dfs(1, 0);
cout << dp[1];
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
if(fopen("nameholder.inp", "r")){
freopen("nameholder.inp", "r", stdin);
freopen("nameholder.out", "w", stdout);
}
int t = 1;
while(t --){
solve();
cout << "\n";
}
cerr << "Code time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";
return 0;
}
// Whose eyes are those eyes?
