//#define _GLIBCXX_DEBUG
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include <bits/stdc++.h>
using namespace std;
//#include <ext/pb_ds/assoc_container.hpp>
//
//using namespace __gnu_pbds;
//
//template<typename T>
//using ordered_set = tree<T, null_type, less < T>, rb_tree_tag, tree_order_statistics_node_update>;
//template<typename T>
//using normal_queue = priority_queue<T, vector<T>, greater<>>;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
#define trace(x) cout << #x << ": " << (x) << endl;
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define uniq(x) x.resize(unique(all(x)) - begin(x))
#define sz(s) ((int) size(s))
#define pii pair<int, int>
#define mp(x, y) make_pair(x, y)
#define int128 __int128
#define pb push_back
#define popb pop_back
#define eb emplace_back
#define fi first
#define se second
#define itn int
typedef long long ll;
typedef pair<ll, ll> pll;
typedef long double ld;
typedef double db;
typedef unsigned int uint;
template<typename T>
bool ckmn(T &x, T y) {
if (x > y) {
x = y;
return true;
}
return false;
}
template<typename T>
bool ckmx(T &x, T y) {
if (x < y) {
x = y;
return true;
}
return false;
}
int bit(int x, int b) {
return (x >> b) & 1;
}
int rand(int l, int r) { return (int) ((ll) rnd() % (r - l + 1)) + l; }
const ll infL = 3e18;
const int infI = 1000000000 + 7;
const int infM = 0x3f3f3f3f; //a little bigger than 1e9
const ll infML = 0x3f3f3f3f3f3f3f3fLL; //4.5e18
const int N = 200002;
const int mod = 998244353;
const ld eps = 1e-9;
vector<pair<int, int>> g[N], adj[N];
ll dp[2][N];
int p[N], wp[N];
void precalc(int v, int par) {
p[v] = par;
adj[v].clear();
for (auto [to, w]: g[v]) {
if (to != par) {
wp[to] = w;
precalc(to, v);
adj[v].emplace_back(to, w);
}
}
}
void dfs(int v) {
vector<ll> nw;
dp[0][v] = dp[1][v] = 0;
for (auto [to, w]: adj[v]) {
dfs(to);
ll val = max(dp[1][to], dp[0][to]);
dp[0][v] += val;
nw.emplace_back(dp[0][to] + w - val);
}
sort(rall(nw));
if (!nw.empty() && p[v] != -1)
ckmx(dp[1][v], dp[0][v] + nw[0] + wp[v]);
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n;
cin >> n;
for (int i = 1; i < n; ++i) {
int a, b, w;
cin >> a >> b >> w;
--a, --b;
g[a].emplace_back(b, w);
g[b].emplace_back(a, w);
}
ll ans = -infL;
for (int i = 0; i < n; ++i) {
precalc(i, -1);
dfs(i);
ckmx(ans, max(dp[1][i], dp[0][i]));
}
cout << ans;
return 0;
}
