#include <bits/stdc++.h>
using namespace std;
#define pii pair <int , int>
#define F first
#define S second
const int N = 1e5 + 10, inf = 1e9 + 5;
int dp[N][2];
vector <pii> g[N];
void dfs(int v, int p = 0)
{
int sum = 0;
for (pii u : g[v]) if (u.F != p) {
dfs(u.F, v);
sum += max(dp[u.F][1] + u.S, dp[u.F][0]);
}
dp[v][0] = sum;
for (pii u : g[v]) if (u.F != p)
dp[v][1] = max(dp[v][1], sum - max(dp[u.F][1] + u.S, dp[u.F][0]) + dp[u.F][0] + u.S);
}
int main()
{
int n; cin >> n;
for (int i = 0; i < n - 1; i++) {
int u, v, w; cin >> u >> v >> w;
g[u].push_back({v, w});
g[v].push_back({u, w});
}
int ans = 0;
for (int i = 1; i <= n; i++) {
for (int i = 1; i <= n; i++) dp[i][0] = dp[i][1] = -inf;
dfs(i);
ans = max(ans, dp[i][0]);
}
cout << ans << "\n";
}
