#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
#define FOR(i,a,b) for(int i = (a) , _b = (b); i <= _b; ++i)
#define sz(s) (int)(s).size()
#define MASK(x) ((LL)(1)<<(x))
#define BIT(mask,x) (((mask)>>(x))&(1))
template<class X,class Y>
bool maximize(X &x ,Y y){
if (x < y) return x = y , true; else return false;
}
template<class X,class Y>
bool minimize(X &x ,Y y){
if (x > y) return x = y , true; else return false;
}
template<class T>
void compress(vector<T>&data){
sort(data.begin() , data.end());
data.resize(unique(data.begin() , data.end()) - data.begin());
return;
}
template<class X,class Y>
Y Find(vector<X>&data,Y y){
return upper_bound(data.begin() , data.end() , y) - data.begin();
}
const int N = (int) 1e5;
const int MAXLOG = (int) 17;
int par[N + 2][MAXLOG + 2] = {} , h[N + 2] = {};
int sta[N + 2] = {} , fin[N + 2] = {} , time_dfs = 0;
vector<int>ke[N + 2];
void add_canh(int u , int v){
ke[u].push_back(v) , ke[v].push_back(u);
return;
}
struct Node{
int u , v , c;
};
vector<Node> ask[N + 2];
int n , m;
void pre_dfs(int u , int p){
par[u][0] = p;
h[u] = h[p] + 1;
for(int i = 1; i <= MAXLOG; ++i) par[u][i] = par[par[u][i - 1]][i - 1];
sta[u] = ++time_dfs;
for(int v : ke[u]){
if (v == p) continue;
pre_dfs(v , u);
}
fin[u] = time_dfs;
return;
}
int LCA(int u , int v){
if (h[u] < h[v]) swap(u , v);
for(int i = MAXLOG; i >= 0; --i){
if (h[par[u][i]] >= h[v]) u = par[u][i];
}
if (u == v) return u;
for(int i = MAXLOG; i >= 0; --i){
if (par[u][i] != par[v][i]){
u = par[u][i] , v = par[v][i];
}
}
return par[u][0];
}
class IT{
public:
vector<LL>st;
void load_size(int n){
st = vector<LL>(n * 4 + 2 , 0);
return;
}
void update(int id , int l , int r , int pos , LL val){
if (l > pos || r < pos) return;
if (l == r) st[id] += val;
else{
int m = (l + r) / 2;
if (pos <= m) update(id * 2 , l , m , pos , val);
else update(id * 2 + 1 , m + 1 , r , pos , val);
st[id] = st[id * 2] + st[id * 2 + 1];
}
return;
}
LL Get(int id , int l , int r , int u , int v){
if (l > v || r < u) return 0;
if (u <= l && r <= v) return st[id];
int m = (l + r) / 2;
return Get(id * 2 , l , m , u , v) + Get(id * 2 + 1 , m + 1 , r , u , v);
}
};
IT st;
LL dp[N + 2] = {};
void add_range(int u , LL cost){
st.update(1 , 1 , time_dfs , sta[u] , cost);
st.update(1 , 1 , time_dfs , fin[u] + 1 , -cost);
return;
}
LL Get(int u){
return st.Get(1 , 1 , time_dfs , 1 , sta[u]);
}
void dfs(int u , int p){
LL tot = 0;
for(int v : ke[u]){
if (v == p) continue;
dfs(v , u);
tot += dp[v];
}
add_range(u , tot);
dp[u] = tot;
for(auto & x : ask[u]){
LL new_c = Get(x.u) + Get(x.v) - Get(u) + x.c;
maximize(dp[u] , new_c);
}
add_range(u , -dp[u]);
return;
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0) ; cout.tie(0) ;
#define name "main"
if (fopen(name".inp","r")){
freopen(name".inp","r",stdin);
freopen(name".out","w",stdout);
}
cin >> n ;
FOR(i , 1 , n - 1){
int u , v; cin >> u >> v;
add_canh(u , v);
}
cin >> m;
pre_dfs(1 , 0);
st.load_size(time_dfs);
// for(int i = 1; i <= n; ++i) cout << sta[i] << ' ' << fin[i] << '\n';
FOR(i , 1 , m){
int a , b , c; cin >> a >> b >> c;
int lca = LCA(a , b);
ask[lca].push_back({a , b , c});
}
dfs(1 , 0);
cout << dp[1] << '\n';
// for(int i = 1; i <= n; ++i) cout << dp[i] << '\n';
return 0;
}
