#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
const int INF = (int) 1e9 + 1e6 + 123;
const ll LINF = (ll) 1e18 + 1e9 + 123;
const ld EPS = (ld) 1e-7;
const ll MOD = (ll) 1e9 + 7;
#define sz(x) (int) (x).size()
#define mp(x, y) make_pair(x, y)
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define lb(s, t, x) (int) (lower_bound(s, t, x) - s)
#define ub(s, t, x) (int) (upper_bound(s, t, x) - s)
#define rep(i, f, t) for (int i = f; i < t; i++)
#define per(i, f, t) for (int i = f; i >= t; i--)
ll power(ll x, ll y, ll mod = MOD) {
if (y == 0) {
return 1;
}
if (y & 1) {
return power(x, y - 1, mod) * x % mod;
} else {
ll tmp = power(x, y / 2, mod);
return tmp * tmp % mod;
}
}
template<typename A, typename B> bool mini(A &x, const B &y) {
if (y < x) {
x = y;
return true;
}
return false;
}
template<typename A, typename B> bool maxi(A &x, const B &y) {
if (y > x) {
x = y;
return true;
}
return false;
}
void add(ll &x, ll y) {
x += y;
if (x >= MOD) x -= MOD;
if (x < 0) x += MOD;
}
ll mult(ll x, ll y) {
return x * y % MOD;
}
void run();
#define TASK ""
int main() {
#ifdef LOCAL
if (strlen(TASK) > 0) {
cerr << "Reminder: you are using file i/o, filename: " TASK "!" << endl << endl;
}
#endif
#ifndef LOCAL
if (strlen(TASK)) {
freopen(TASK ".in", "r", stdin);
freopen(TASK ".out", "w", stdout);
}
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
#endif
cout << fixed << setprecision(12);
run();
return 0;
}
// == SOLUTION == //
const int N = (int) 2e5 + 123;
int n;
vector<pair<int, int>> g[N];
int take[N], ntake[N];
void dfs(int v, int f = -1, int up_cost = 0) {
int id = -1;
rep(i, 0, sz(g[v])) {
int u = g[v][i].first;
if (u == f) {
id = i;
continue;
}
dfs(u, v, g[v][i].second);
}
if (id != -1) {
swap(g[v][id], g[v][sz(g[v]) - 1]);
g[v].pop_back();
}
int sum = 0;
for (auto &it : g[v]) {
int u = it.first;
sum += take[u];
}
ntake[v] = sum;
if (f != -1) {
for (auto &it : g[v]) {
int u = it.first;
sum -= take[u];
sum += ntake[u];
maxi(take[v], sum + up_cost + it.second);
sum += take[u];
sum -= ntake[u];
}
}
vector<int> deltas;
for (auto &it : g[v]) {
int u = it.first;
deltas.pb(ntake[u] - take[u] + it.second);
}
sort(all(deltas));
reverse(all(deltas));
if (sz(deltas) >= 2) {
maxi(ntake[v], sum + deltas[0] + deltas[1]);
}
maxi(take[v], ntake[v]);
}
void run() {
cin >> n;
rep(i, 1, n) {
int u, v, c;
cin >> u >> v >> c;
g[u].pb({v, c});
g[v].pb({u, c});
}
dfs(1);
cout << take[1] << "\n";
}
