#include<bits/stdc++.h>
#define pii pair<int,int>
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define pf push_front
#define pb2 pop_back
#define pf2 pop_front
#define line printf("\n")
#define pq priority_queue
#define rep(k,i,j) for(int k = (int)i;k<(int)j;k++)
#define repd(k,i,j) for(int k = (int)i;k>=(int)j;k--)
#define ll long long
#define ALL(a) a.begin(),a.end()
#define vi vector<int>
using namespace std;
int INF = 1e9+7;
#define vvi vector<vi>
int N, M;
vi A, B, C;
vvi adj;
void bfs(int u, int v, vi &path) {
vi par(N, -1);
queue<int> q;
q.push(u); par[u] = u;
while (q.size()) {
int a = q.front(); q.pop();
for (int b : adj[a]) if (par[b] == -1) {
q.push(b);
par[b] = a;
}
}
for (int b = v, a = par[v]; b != u; b = par[b], a = par[a]) {
path.pb(b);
}
path.pb(u);
}
void read(int _N, int _M, vi U, vi V, vi _A, vi _B, vi _C) {
tie(N, M, A, B, C) = {_N, _M, _A, _B, _C};
adj.resize(N);
rep(k, 0, N - 1) {
U[k]--; V[k]--;
adj[U[k]].pb(V[k]);
adj[V[k]].pb(U[k]);
}
rep(k, 0, M) {
A[k]--; B[k]--;
}
}
vi DP, path, rev;
vvi L, cost;
int dp(int a) {
if (a < 0) return 0;
int &ret = DP[a];
if (ret != -1) return ret;
ret = dp(a - 1);
rep(k, 0, L[a].size()) {
int left = L[a][k], val = cost[a][k];
ret = max(ret, dp(left - 1) + val);
}
return ret;
}
int getMaximumVotes(int _N, int _M, vi _U, vi _V, vi _A, vi _B, vi _C) {
read(_N, _M, _U, _V, _A, _B, _C);
// check degree
rep(k, 0, N) if (adj[k].size() > 2)
return -1;
vi leaf;
rep(k, 0, N) if (adj[k].size() == 1)
leaf.pb(k);
bfs(leaf[0], leaf[1], path);
rev = vi(N);
rep(k, 0, N)
rev[path[k]] = k;
L = cost = vvi(N);
rep(k, 0, M) {
A[k] = rev[A[k]], B[k] = rev[B[k]];
if (A[k] > B[k])
swap(A[k], B[k]);
L[B[k]].pb(A[k]);
cost[B[k]].pb(C[k]);
}
// rep(k, 0, N) printf("%")
DP = vi(N, -1);
return dp(N - 1);
}
// grader.cpp
#include <stdio.h>
#include <vector>
int main() {
int N, M;
std::vector<int> U, V;
std::vector<int> A, B, C;
scanf("%d", &N);
U.resize(N-1); V.resize(N-1);
for (int i = 0 ; i < N-1 ; i++) {
scanf("%d %d", &U[i], &V[i]);
}
scanf("%d", &M);
A.resize(M); B.resize(M); C.resize(M);
for (int i = 0 ; i < M ; i++) {
scanf("%d %d %d", &A[i], &B[i], &C[i]);
}
int ans = getMaximumVotes(N, M, U, V, A, B, C);
printf("%d\n", ans);
return 0;
}
