#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <string>
#include <cmath>
#include <cstdio>
#include <iomanip>
#include <fstream>
#include <cassert>
#include <cstring>
#include <unordered_set>
#include <unordered_map>
#include <numeric>
#include <ctime>
#include <bitset>
#include <complex>
#include <chrono>
#include <random>
#include <functional>
using namespace std;
#define int long long
const int INF = 1e18 + 239;
const int N = 2e5 + 7;
int to[N];
int dp[N][2];
vector<pair<int, int>> g[N];
void dfs(int cur, int p) {
int S = 0;
int mx = -INF;
for (auto [t, w] : g[cur]) {
if (t != p) {
to[t] = w;
dfs(t, cur);
S += max(dp[t][0], dp[t][1]);
mx = max(mx, dp[t][0] + to[t] - max(dp[t][0], dp[t][1]));
}
}
dp[cur][1] = S + mx + to[cur];
dp[cur][0] = S;
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
for (int i = 0; i + 1 < n; i++) {
int u, v, w;
cin >> u >> v >> w;
u--;
v--;
g[u].push_back({v, w});
g[v].push_back({u, w});
}
int ans = 0;
for (int i = 0; i < n; i++) {
dfs(i, -1);
ans = max(ans, dp[i][0]);
}
cout << ans << '\n';
}
