#include <bits/stdc++.h>
using namespace std;
int const NMAX=100005;
int const LOG=20;
int n,m;
vector<int>tree[NMAX];
void read(){
cin>>n;
int i;
for(i=1;i<n;++i){
int u,v;
cin>>u>>v;
tree[u].push_back(v);
tree[v].push_back(u);
}
}
int lift[NMAX][LOG];
int h[NMAX];
int tin[NMAX],tout[NMAX];
void dfs(int nod){
int i;
static int time=0;
tin[nod]=++time;
for(i=1;i<LOG;++i)
lift[nod][i]=lift[lift[nod][i-1]][i-1];
for(auto fiu : tree[nod])
if(fiu!=lift[nod][0]){
lift[fiu][0]=nod;
h[fiu]=h[nod]+1;
dfs(fiu);
}
tout[nod]=time;
}
struct path{
int u,v,cost;
}paths[NMAX];
vector<int>ids[NMAX];
int lca(int u,int v){
if(h[u]<h[v])
swap(u,v);
int dh=h[u]-h[v];
int i;
for(i=0;i<LOG;++i)
if(dh&(1<<i))
u=lift[u][i];
if(u==v)
return u;
for(i=LOG-1;i>=0;--i)
if(lift[u][i]!=lift[v][i]){
u=lift[u][i];
v=lift[v][i];
}
return lift[u][0];
}
void read_paths(){
cin>>m;
int i;
for(i=1;i<=m;++i){
int u,v,cost;
cin>>u>>v>>cost;
paths[i]={u,v,cost};
ids[lca(u,v)].push_back(i);
}
}
int ub(int x){
return x&(-x);
}
struct fenwick_tree{
long long v[NMAX];
void upd(int pos,long long val){
while(pos<=n){
v[pos]+=val;
pos+=ub(pos);
}
}
long long qry(int pos){
long long s=0;
while(pos){
s+=v[pos];
pos-=ub(pos);
}
return s;
}
}aib;
void maxself(long long& x,long long val){
if(x<val)
x=val;
}
long long solve(int nod){
long long sum=0;
for(auto fiu : tree[nod])
if(fiu!=lift[nod][0])
sum+=solve(fiu);
long long ans=0;
for(auto id : ids[nod]){
auto [u,v,cost]=paths[id];
maxself(ans,cost+aib.qry(tin[u])+aib.qry(tin[v]));
}
aib.upd(tin[nod],-ans);
aib.upd(tout[nod]+1,ans);
return ans+sum;
}
int main()
{
read();
dfs(1);
read_paths();
cout<<solve(1);
return 0;
}
