#include <iostream>
#include<cstring>
#include<vector>
using namespace std;
vector<int> g[100005];
bool ok[20][20];
int done[100005];
bool dfs(int node, int par, int t) {
done[node]++;
if (node == t) return 1;
for (auto x : g[node])
if (x != par)
if (dfs(x, node, t)) return 1;
done[node]--;
return 0;
}
int main()
{
int n; 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);
}
int m; cin >> m;
vector<pair<int, int>> q(m);
vector<int> c(m);
for (int i = 0; i < m; ++i)
cin >> q[i].first >> q[i].second >> c[i];
for(int i = 0; i < m; ++i)
for (int j = i + 1; j < m; ++j){
dfs(q[i].first, -1, q[i].second);
dfs(q[j].first, -1, q[j].second);
bool y = 1;
for (int i = 1; i <= n; ++i)
if (done[i] > 1) y = 0;
ok[i][j] = ok[j][i] = y;
memset(done, 0, sizeof(done));
}
int ans = 0;
for (int i = 0; i < (1 << m); ++i) {
vector<int> a;
for (int j = 0; j < m; ++j)
if (i & (1 << j)) a.push_back(j);
bool y = 1;
for (int x = 0; x < a.size(); ++x)
for (int j = x + 1; j < a.size(); ++j)
if (!ok[a[x]][a[j]]) y = 0;
if (!y) continue;
int cur = 0;
for (auto x : a) cur += c[x];
ans = max(ans, cur);
}
cout << ans;
}
