#include <bits/stdc++.h>
#include <ios>
#include <iostream>
using namespace std;
using ll = long long;
using P = pair<int, int>;
#define f first
#define s second
const int MOD = 1e9+7;
const ll MX = 4*1e18;
vector<vector<P>> adj;
vector<ll> dp1; // just best overall niger
vector<ll> dp2; // best given that you have a 1 extension to some child
void calc(int nd, int pr) {
// cout << "nd, pr: " << nd << ", " << pr << "\n";
if (nd != pr && adj[nd].size() == 1) { // leaf nigga
return;
}
vector<ll> cst(adj[nd].size());
int idx = 0;
for (auto c: adj[nd]) {
if (c.f != pr) {
int mx = 0;
// cout << "c.f, c.s: " << c.f << ", " << c.s << "\n";
// cout << "adj[c.f].size, c.s+dp1[c.f]: " << adj[c.f].size() << ", " << c.s+dp1[c.f] << "\n";
mx = max((adj[c.f].size() > 1 ? c.s+dp1[c.f] : 0), dp2[c.f]);
// cout << "mx: " << mx << "\n";
cst[idx] = mx;
idx++;
dp2[nd] += mx;
}
}
ll ovr = dp2[nd];
ll lhs = 0;
idx = 0;
for (auto c: adj[nd]) {
if (c.f != pr) {
ovr -= cst[idx];
dp1[nd] = max(dp1[nd], lhs+ovr+dp2[c.f]+c.s);
lhs += cst[idx];
idx++;
}
}
}
ll mx = 0;
void dfs(int nd, int pr) {
for (auto c: adj[nd]) {
if (c.f != pr) {
dfs(c.f, nd);
}
}
calc(nd, pr);
}
void dfs2(int nd, int pr) {
for (auto c: adj[nd]) {
if (c.f != pr) {
ll nd1 = dp1[nd];
ll nd2 = dp2[nd];
ll c1 = dp1[c.f];
ll c2 = dp2[c.f];
dp1[nd] = 0; dp2[nd] = 0;
dp1[c.f] = 0; dp2[c.f] = 0;
calc(nd, c.f);
calc(c.f, c.f);
dfs2(c.f, nd);
dp1[nd] = nd1;
dp2[nd] = nd2;
dp1[c.f] = c1;
dp2[c.f] = c2;
}
}
mx = max(mx, dp2[nd]);
}
int main() {
int n; cin >> n;
adj.assign(n, vector<P>());
dp1.assign(n, 0);
dp2.assign(n, 0);
for (int i = 0; i < n-1; i++) {
ll a, b, c; cin >> a >> b >> c;
adj[--a].push_back({--b, c});
adj[b].push_back({a, c});
}
dfs(0, 0);
dfs2(0, 0);
cout << mx;
// int tst = 10;
// dfs(tst, tst);
// calc(0, 4);
// calc(4, 4);
// cout << dp2[tst] << "\n";
}
