#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 2e5 + 10;
const int inf = 1e8;
int dp[maxn], pd[maxn];
vector<pair<int, int> > t[maxn];
void dfs(int v, int par = -1){
int mx = -inf;
dp[v] = 0;
for (auto edge : t[v]){
int u = edge.first, c = edge.second;
if (u != par){
dfs(u, v);
dp[v] += max(dp[u], pd[u] + c);
mx = max(mx, dp[u] + c - max(dp[u], pd[u] + c));
}
}
pd[v] = dp[v] + mx;
}
int main(){
ios_base::sync_with_stdio (false);
int n;
cin >> n;
for (int i = 1; i <= n - 1; i++){
int v, u, c;
cin >> v >> u >> c;
t[v].push_back({u, c});
t[u].push_back({v, c});
}
int answer = 0;
for (int v = 1; v <= n; v++){
dfs(v);
answer = max(answer, dp[v]);
}
cout << answer << endl;
}
