#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define dbg(...) 47
#endif
constexpr int N = 1e5;
vector<int> g[N];
vector<array<int, 3>> t[N];
int to[N][20], lvl[N], dp[N], in[N], out[N];
int timer = 0;
void init(int u, int p) {
in[u] = timer++;
to[u][0] = p;
for (int i = 1; i < 20; i++) {
to[u][i] = to[to[u][i - 1]][i - 1];
}
for (auto v : g[u]) {
if (v != p) {
lvl[v] = lvl[u] + 1;
init(v, u);
}
}
out[u] = timer - 1;
}
int lca(int x, int y) {
if (lvl[x] < lvl[y]) {
swap(x, y);
}
int d = lvl[x] - lvl[y];
for (int i = 0; i < 20; i++) {
if (d & (1 << i)) {
x = to[x][i];
}
}
if (x == y) {
return x;
}
for (int i = 19; i >= 0; i--) {
if (to[x][i] != to[y][i]) {
x = to[x][i];
y = to[y][i];
}
}
return to[x][0];
}
void dfs(int u, int p) {
int s = 0;
for (auto v : g[u]) {
if (v == p) continue;
dfs(v, u);
s += dp[v];
}
dp[u] = s;
for (auto [a, b, c] : t[u]) {
int cur = s + c;
if (a != u) {
for (auto x : g[u]) {
if (x == p) continue;
if (in[x] <= in[a] && out[a] <= out[x]) {
cur -= dp[x];
}
}
for (auto x : g[a]) {
if (x == to[a][0]) continue;
cur += dp[x];
}
}
if (b != u) {
for (auto x : g[u]) {
if (x == p) continue;
if (in[x] <= in[b] && out[b] <= out[x]) {
cur -= dp[x];
}
}
for (auto x : g[b]) {
if (x == to[b][0]) continue;
cur += dp[x];
}
}
dp[u] = max(dp[u], cur);
}
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n;
cin >> n;
for (int i = 1; i < n; i++) {
int x, y;
cin >> x >> y;
x--; y--;
g[x].push_back(y);
g[y].push_back(x);
}
init(0, 0);
int m;
cin >> m;
for (int i = 0; i < m; i++) {
int a, b, c;
cin >> a >> b >> c;
a--; b--;
t[lca(a, b)].push_back({a, b, c});
}
dfs(0, 0);
cout << dp[0] << '\n';
return 0;
}
