#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif
const int N = 1e5 + 5, LG = 17;
int n, m;
int pr[LG][N], s[N], dp[N], L[N], R[N], dep[N];
vector<int> g[N];
vector<array<int, 3>> cands[N];
void upd(int i, int x) {
for (; i <= n; i += i & -i) {
s[i] += x;
}
}
void upd(int l, int r, int x) {
upd(l, x);
upd(r + 1, -x);
}
int qry(int i) {
int res = 0;
for (; i; i -= i & -i) {
res += s[i];
}
return res;
}
int timer;
void pre_dfs(int u) {
L[u] = ++timer;
for (int v : g[u]) {
if (v != pr[0][u]) {
dep[v] = dep[u] + 1;
pr[0][v] = u;
for (int j = 1; j < LG; ++j) {
pr[j][v] = pr[j - 1][pr[j - 1][v]];
}
pre_dfs(v);
}
}
R[u] = timer;
}
int lca(int u, int v) {
if (dep[u] < dep[v]) {
swap(u, v);
}
for (int j = LG - 1; ~j; --j) {
if (dep[u] - (1 << j) >= dep[v]) {
u = pr[j][u];
}
}
if (u == v) {
return u;
}
for (int j = LG - 1; ~j; --j) {
if (pr[j][u] != pr[j][v]) {
u = pr[j][u], v = pr[j][v];
}
}
return pr[0][u];
}
void dfs(int u) {
int sum = 0;
for (int v : g[u]) {
if (v != pr[0][u]) {
dfs(v);
sum += dp[v];
}
}
dp[u] = sum;
for (auto [x, y, w] : cands[u]) {
dp[u] = max(dp[u], qry(L[x]) + qry(L[y]) + w + sum);
}
upd(L[u], R[u], sum - dp[u]);
}
int main() {
ios::sync_with_stdio(false); cin.tie(nullptr);
cin >> n;
for (int i = 1; i < n; ++i) {
int u, v; cin >> u >> v;
g[u].push_back(v);
g[v].push_back(u);
}
pre_dfs(1);
cin >> m;
while (m--) {
int u, v, w; cin >> u >> v >> w;
cands[lca(u, v)].push_back({u, v, w});
}
dfs(1);
cout << dp[1];
return 0;
}
