#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define int long long
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) a.begin(),a.end()
const int mxN = (int)1e5+10;
const int LINF = (int)1e18;
int n, m, x, y;
vector<int> adj[mxN];
int node[mxN], dp[mxN];
struct road{ int a, b, c; };
road v[mxN];
bool dfs(int s, int t, int v, int p){
if(s==t) return true;
for(auto u : adj[s]){
if(u==p) continue;
if(dfs(u,t,v,s)){ node[u]+=v; return 1; }
}
return 0;
}
void add(int s, int t, int v){
// this can be done in O(logN) or O(1) with sparse tables...
node[s]+=v; dfs(s,t,v,-1);
}
int32_t main()
{
ios_base::sync_with_stdio(false); cin.tie(0);
cin >> n; int ans = 0;
for(int i = 1; i < n; i++){
int x, y; cin >> x >> y;
adj[x].pb(y), adj[y].pb(x);
}
cin >> m;
vector<int> xd; xd.pb(0);
for(int i = 0; i < m; i++){
cin >> v[i].a >> v[i].b >> v[i].c;
if(v[i].a>v[i].b) swap(v[i].a,v[i].b);
xd.pb(v[i].b);//, xd.pb(v[i].b);
}
sort(v,v+m,[&](road x, road y){ return x.b<y.b; });
sort(all(xd));
for(int i = 0; i < m; i++){
int a = v[i].a, b = v[i].b, c = v[i].c;
int pr = xd[lower_bound(all(xd),v[i].a)-begin(xd)-1];
int pr2 = xd[lower_bound(all(xd),v[i].b)-begin(xd)-1];
dp[b] = max({dp[b],dp[pr2],dp[pr]+c});
ans = max(ans, dp[b]);
}
cout << ans;
}
