#include <bits/stdc++.h>
#define int long long
using namespace std;
int a;
vector<int> z[1000005];
int logarit[1000005];
int sta[1000005], fin[1000005], high[1000005];
int euler[2000005], st[2000005][21]; // cần gấp đôi kích thước euler
int tour;
struct node {
int x, y, val;
};
node q[1000005];
vector<int> pos[1000005];
void dfs(int u, int par) {
sta[u] = ++tour;
euler[tour] = u;
for (int v : z[u]) {
if (v == par) continue;
high[v] = high[u] + 1;
dfs(v, u);
euler[++tour] = u;
}
fin[u] = tour;
}
void build_log() {
logarit[1] = 0;
for (int i = 2; i <= 2 * a; i++) {
logarit[i] = logarit[i / 2] + 1;
}
}
void build_st() {
for (int i = 1; i <= tour; i++) {
st[i][0] = euler[i];
}
for (int j = 1; (1 << j) <= tour; j++) {
for (int i = 1; i + (1 << j) - 1 <= tour; i++) {
int u = st[i][j - 1];
int v = st[i + (1 << (j - 1))][j - 1];
st[i][j] = (high[u] < high[v] ? u : v);
}
}
}
int lca(int u, int v) {
int l = sta[u], r = sta[v];
if (l > r) swap(l, r);
int j = logarit[r - l + 1];
int u1 = st[l][j];
int u2 = st[r - (1 << j) + 1][j];
return (high[u1] < high[u2]) ? u1 : u2;
}
int bit[1000005];
void update(int i, int val) {
i++;
while (i <= tour) {
bit[i] += val;
i += i & -i;
}
}
int query(int i) {
i++;
int res = 0;
while (i > 0) {
res += bit[i];
i -= i & -i;
}
return res;
}
int dfs1(int u, int par) {
int sum = 0;
for (int v : z[u]) {
if (v == par) continue;
sum += dfs1(v, u);
}
int best = 0;
for (int id : pos[u]) {
auto [x, y, val] = q[id];
int pre = val + query(sta[x]) + query(sta[y]);
best = max(best, pre);
}
update(sta[u], -best);
update(fin[u] + 1, best);
return sum + best;
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cin >> a;
for (int i = 1; i < a; i++) {
int u, v;
cin >> u >> v;
z[u].push_back(v);
z[v].push_back(u);
}
dfs(1, 0);
build_log();
build_st();
int c;
cin >> c;
for (int i = 1; i <= c; i++) {
int x, y, val;
cin >> x >> y >> val;
int l = lca(x, y);
pos[l].push_back(i);
q[i] = {x, y, val};
}
cout << dfs1(1, 0) << "\n";
return 0;
}
