#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
#define fi first
#define se second
#define vi vector<int>
#define vll vector<long long>
#define pii pair<int, int>
#define pll pair<long long, long long>
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
mt19937_64 rng64(chrono::high_resolution_clock::now().time_since_epoch().count());
inline int rand(int l,int r){return uniform_int_distribution<int>(l, r)(rng);}
inline ll rand(ll l,ll r){return uniform_int_distribution<ll>(l, r)(rng64);}
#ifdef DEBUG
auto&operator<<(auto&o,pair<auto,auto>p){return o<<"("<<p.first<<", "<<p.second<<")";}
auto operator<<(auto&o,auto x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<","+!i++<<e;return o<<"}";}
#define debug(X...)cerr<<"["#X"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(X)
#else
#define debug(...){}
#endif
struct custom_hash {
static uint64_t splitmix64(uint64_t x) {
x += 0x9e3779b97f4a7c15;
x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
return x ^ (x >> 31);
}
size_t operator()(uint64_t x) const {
static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
return splitmix64(x + FIXED_RANDOM);
}
};
struct pair_hash{
size_t operator()(const pair<int,int>&x)const{
return hash<long long>()(((long long)x.first)^(((long long)x.second)<<32));
}
};
const int MAXN = 1e5 + 7;
const int MAXK = 18;
const int B = 369;
int dep[MAXN];
int jump[MAXK][MAXN];
ll dp[MAXN];
int bigJump[MAXN];
int parent[MAXN];
ll sumOnBigJump[MAXN];
ll sumOfChild[MAXN];
ll dp[MAXN];
vi g[MAXN];
vector<pair<pii, int>> vec[MAXN];
int n, m;
void dfs(int v, int p, int d){
dep[v] = d;
parent[v] = p;
for(auto u : g[v]){
if(u != p){
dfs(u, v, d + 1);
}
}
}
void init(){
dfs(1, 1, 0);
for(int i = 1; i <= n; i++){
int L = B;
int x = i;
while(L){
x = parent[x];
L--;
}
bigJump[i] = x;
jump[0][i] = parent[i];
}
for(int j = 1; j < MAXK; j++){
for(int i = 1; i <= n; i++){
jump[j][i] = jumo[j - 1][jump[j - 1][i]];
}
}
}
int lca(int u, int v){
if(dep[u] > dep[v]){
swap(u, v);
}
for(int j = MAXK - 1; j >= 0; j--){
if(dep[v] - (1 << j) >= dep[u]){
v = jump[j][v];
}
}
if(u == v){
return u;
}
for(int j = MAXK - 1; j >= 0; j--){
if(jump[j][u] != jump[j][v]){
u = jump[j][u];
v = jump[j][v];
}
}
return parent[v];
}
void add(int a, int b, int c){
if(dep[a] < dep[b]){
swap(a, b);
}
int x = lca(a, b);
if(x == b){
vec[x].pb(mp(mp(a, -1), c));
}else{
vec[x].pb(mp(mp(a, b), c));
}
}
void updDp(int v){
if(v == 1){
return;
}
sumOfChild[parent[v]] += dp[v];
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
cin >> n;
for(int i = 1; i < n; i++){
int a, b;
cin >> a >> b;
g[a].pb(b);
g[b].pb(a);
}
init();
for(int i = 1; i <= m; i++){
int a, b, c;
cin >> a >> b >> c;
add(a, b, c);
}
solve(1, 1);
cout << dp[1] << '\n';
return 0;
}
