#include <iostream>
#include <vector>
#define f first
#define s second
using namespace std;
int n, m, p[100010][20], d[100010], sub[100010], dp[100010];
pair<int,int> group[100010];
vector<int> edge[100010];
vector<pair<pair<int,int>,int>> add[100010];
vector<vector<int>> grp, ps, pss;
void dfs1(int u, int v, int depth) {
p[u][0] = v;
d[u] = depth;
sub[u] = 1;
for (int i = 1; i < 20; i++) p[u][i] = p[p[u][i-1]][i-1];
for (int i = 0; i < edge[u].size(); i++) if (edge[u][i] != v) dfs1(edge[u][i],u,depth+1), sub[u] += sub[edge[u][i]];
}
int lca(int u, int v) {
if (d[u] < d[v]) swap(u,v);
int i = 19;
while (i >= 0) {
if (d[p[u][i]] >= d[v]) u = p[u][i];
i--;
}
if (u == v) return u;
i = 19;
while (i >= 0) {
if (p[u][i] != p[v][i]) u = p[u][i], v = p[v][i];
i--;
}
return p[u][0];
}
void hld(int u, int v, int newgrp) {
if (newgrp) {
grp.push_back({u});
ps.push_back({0,0});
pss.push_back({0,0});
group[u] = {grp.size()-1,0};
} else {
grp[group[v].f].push_back(u);
ps[group[v].f].push_back(0);
pss[group[v].f].push_back(0);
group[u] = {group[v].f,group[v].s+1};
}
for (int i = 0; i < edge[u].size(); i++) if (edge[u][i] != v) hld(edge[u][i],u,(sub[edge[u][i]] <= (sub[u]-1)/2));
}
int sum(int u, int v) {
if (d[u] < d[v]) return 0;
if (group[u].f == group[v].f) return ps[group[v].f][group[v].s]-ps[group[u].f][group[u].s+1];
return ps[group[u].f][0]-ps[group[u].f][group[u].s+1]+sum(p[grp[group[u].f][0]][0],v);
}
int summ(int u, int v) {
if (d[u] < d[v]) return 0;
if (group[u].f == group[v].f) return pss[group[v].f][group[v].s]-pss[group[u].f][group[u].s+1];
return pss[group[u].f][0]-pss[group[u].f][group[u].s+1]+summ(p[grp[group[u].f][0]][0],v);
}
void dfs(int u, int v) {
for (int i = 0; i < edge[u].size(); i++) {
if (edge[u][i] != v) {
dfs(edge[u][i],u);
dp[u] += dp[edge[u][i]];
}
}
ps[group[u].f][group[u].s] = ps[group[u].f][group[u].s+1]+dp[u];
pss[group[u].f][group[u].s] = pss[group[u].f][group[u].s+1];
int tmp = dp[u];
for (int i = 0; i < add[u].size(); i++) dp[u] = max(dp[u],add[u][i].s+sum(add[u][i].f.f,u)-summ(add[u][i].f.f,u)+sum(add[u][i].f.s,u)-summ(add[u][i].f.s,u)-tmp);
pss[group[u].f][group[u].s] += dp[u];
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n;
for (int i = 1; i < n; i++) {
int u, v;
cin >> u >> v;
edge[u].push_back(v);
edge[v].push_back(u);
}
dfs1(1,0,1);
cin >> m;
for (int i = 1; i <= m; i++) {
int u, v, w;
cin >> u >> v >> w;
add[lca(u,v)].push_back({{u,v},w});
}
hld(1,0,1);
dfs(1,0);
cout << dp[1] << endl;
}
