#include <bits/stdc++.h>
using namespace std;
#define ii pair<int, int>
#define fi first
#define se second
// #define int long long
#define ll long long
#define ld double
#define mp make_pair
#define lg2 30
#define iii pair<int, ii>
#define iiii pair<ii, ii>
#define base 29
#define eps 1e-8
#define MASK(i) (1LL << (i))
#define BIT(S, i) (((S) >> (i)) & 1)
int dx[] = {0LL, 0LL, 1, -1, 1, 1, -1, -1};
int dy[] = {1, -1, 0LL, 0LL, 1, -1, 1, -1};
const int maxn = 1e5 + 5;
const int mod = 1e9 + 7;
int n, m, x[maxn], y[maxn], a[maxn], b[maxn], c[maxn], h[maxn], tin[maxn], tout[maxn], timer, P[maxn][lg2 + 1], dp[maxn], dp2[maxn];
vector<int> g[maxn], pos[maxn];
void dfs(int u, int cha)
{
tin[u] = ++timer;
for (int v : g[u])
{
if (v == cha)
continue;
P[v][0] = u;
h[v] = h[u] + 1;
dfs(v, u);
}
tout[u] = timer;
}
void build_lca()
{
for (int j = 1; j <= lg2; j++)
{
for (int i = 1; i <= n; i++)
P[i][j] = P[P[i][j - 1]][j - 1];
}
}
int lca(int u, int v)
{
if (h[u] < h[v])
swap(u, v);
for (int i = lg2; i >= 0; i--)
{
if (h[u] - h[v] >= (1 << i))
u = P[u][i];
}
if (u == v)
{
return u;
}
for (int i = lg2; i >= 0; i--)
{
if (P[u][i] != P[v][i])
{
u = P[u][i];
v = P[v][i];
}
}
return P[u][0];
}
struct FEN
{
int n;
vector<int> bit;
FEN() {};
FEN(int _n) : bit(n + 1, 0), n(_n + 1) {
};
int get(int r)
{
int ret = 0;
for (; r >= 0; r = (r & (r + 1)) - 1)
ret += bit[r];
return ret;
}
int get(int l, int r)
{
return get(r) - get(l - 1);
}
void update(int idx, int delta)
{
for (; idx < n; idx = idx | (idx + 1))
bit[idx] += delta;
}
void updateRange(int l, int r, int val)
{
update(l, val);
update(r + 1, -val);
}
} bit;
void DFS(int u, int cha)
{
for (int v : g[u])
{
if (v == cha)
continue;
DFS(v, u);
dp2[u] += dp[v];
}
dp[u] = dp2[u];
bit.updateRange(tin[u], tout[u], dp2[u]);
for (int i : pos[u])
{
dp[u] = max(dp[u], bit.get(tin[a[i]]) + bit.get(tin[b[i]]) - 2 * bit.get(tin[P[u][0]]) - dp2[u] + c[i]);
if (u == 5)
{
// cout << ":" << a[i] << " " << b[i] << " " << bit.get(tin[a[i]]) + bit.get(tin[b[i]]) - 2 * bit.get(tin[P[u][0]]) - dp2[tin[u]] + c[i] << '\n';
}
}
// cout << u << " " << dp[u] << " " << dp2[u] << '\n';
bit.updateRange(tin[u], tout[u], -dp[u]);
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
#define task "task"
if (fopen(task ".inp", "r"))
{
freopen(task ".inp", "r", stdin);
freopen(task ".out", "w", stdout);
}
cin >> n;
for (int i = 1; i < n; i++)
{
cin >> x[i] >> y[i];
g[x[i]].push_back(y[i]);
g[y[i]].push_back(x[i]);
}
dfs(1, -1);
build_lca();
cin >> m;
for (int i = 1; i <= m; i++)
{
cin >> a[i] >> b[i] >> c[i];
pos[lca(a[i], b[i])].push_back(i);
}
bit = FEN(n);
DFS(1, -1);
cout << dp[1];
cerr << endl
<< "TIME : " << clock() * 0.001 << "s" << endl;
}
