/*
https://oj.uz/problem/view/JOI15_election_campaign
O(NM) Code
*/
#include<iostream>
#include<vector>
#include<string.h>
#define ll long long
#define pi pair < ll,ll >
#define mp(a,b) make_pair(a,b)
#define MAX_N 100004
using namespace std;
vector < int > graph[MAX_N];
vector < pair < pi,ll > > tours[MAX_N];
ll jump_memo[MAX_N][21];
ll tin[MAX_N],tout[MAX_N],cur_time;
ll dp[MAX_N],S[MAX_N];
int n,m;
int jump(int x,int i) // find 2^i -th ancestor of x
{
if(jump_memo[x][i] != -1)
return jump_memo[x][i];
return jump_memo[x][i] = jump(jump(x,i-1),i-1);
}
bool is_ancestor(int x,int y) // returns if x is ancestor of y
{
return (tin[x] <= tin[y] && tout[x] >= tout[y]);
}
int get_lca(int x,int y)
{
if(is_ancestor(x,y))
return x;
if(is_ancestor(y,x))
return y;
for(int i = 20;i >= 0;i--)
{
if(!is_ancestor(jump(x,i),y))
x = jump(x,i);
}
return jump(x,0);
}
void dfs(int cur,int par)
{
tin[cur] = cur_time++;
jump_memo[cur][0] = par;
for(int i = 0;i < graph[cur].size();i++)
{
int v = graph[cur][i];
if(v == par)
continue;
dfs(v,cur);
}
tout[cur] = cur_time++;
return;
}
void initialize()
{
memset(jump_memo,-1,sizeof jump_memo);
memset(dp,-1,sizeof dp);
dfs(1,1);
return;
}
void input()
{
int a,b,c;
cin >> n;
for(int i = 0;i < n-1;i++)
{
cin >> a >> b;
graph[a].push_back(b);
graph[b].push_back(a);
}
initialize();
cin >> m;
for(int i = 0;i < m;i++)
{
cin >> a >> b >> c;
tours[get_lca(a,b)].push_back(mp(mp(a,b),c));
}
return;
}
ll go(int cur,int par,int target)
{
if(cur == target)
return S[cur];
for(int i = 0;i < graph[cur].size();i++)
{
int v = graph[cur][i];
if(is_ancestor(v,target) && is_ancestor(cur,v))
return go(v,cur,target)+S[cur]-dp[v];
}
}
ll calc(int cur,int par)
{
if(dp[cur] != -1)
return dp[cur];
for(int i = 0;i < graph[cur].size();i++)
{
int v = graph[cur][i];
if(v==par)
continue;
S[cur] += calc(v,cur);
}
dp[cur] = S[cur];
for(int i = 0;i < tours[cur].size();i++)
{
int x = tours[cur][i].first.first;
int y = tours[cur][i].first.second;
int C = tours[cur][i].second;
// cout << "testing route " << x << " -> " << y << ". lca is " << cur << ". Gain is " << C << ". ";
// cout << "to x: " << go(cur,par,x) << " to y: " << go(cur,par,y) << " S: " << S[cur] << " " << go(cur,par,x)+go(cur,par,y) - S[cur] + C << endl;
dp[cur] = max(dp[cur],go(cur,par,x)+go(cur,par,y) - S[cur] + C); // S[cur] is counted twice
}
// cout << "here " << cur << " " << dp[cur] << endl;
return dp[cur];
}
void solve()
{
cout << calc(1,1) << endl;
}
int main()
{
input();
solve();
return 0;
}
