// https://oj.uz/problem/view/APIO14_beads
#include <iostream>
#include <vector>
#include <algorithm>
#include <random>
//typedef std::pair<int,int> ii;
struct dp{
int dp0, dp1;
dp(int dp0, int dp1) : dp0(dp0), dp1(dp1) {};
};
struct edge{
int vertex, weight;
edge(int vertex, int weight) : vertex(vertex), weight(weight) {};
};
std::vector<std::vector<edge>> adjlist;
std::vector<int> parent;
dp dfs(int node) {
int p = parent[node];
adjlist[node].erase(
std::remove_if(adjlist[node].begin(), adjlist[node].end(), [p, node](edge x){return x.vertex == parent[node];}),
adjlist[node].end()
);
dp result (0, -9999999);
for (edge e : adjlist[node]) {
parent[e.vertex] = node;
dp tmp = dfs(e.vertex);
int val = std::max(tmp.dp0, tmp.dp1 + e.weight);
result.dp0 += val;
result.dp1 = std::max(result.dp1, e.weight + tmp.dp0 - val);
}
result.dp1 += result.dp0;
return result;
}
int main() {
int n;
std::cin >> n;
adjlist.resize(n);
for (int i = 1; i < n; ++i) {
int u, v, val;
std::cin >> u >> v >> val;
--u; --v;
adjlist[u].emplace_back(v, val);
adjlist[v].emplace_back(u, val);
}
std::mt19937 engine ((std::random_device())());
std::vector<int> roots (n);
for (int i = 0; i < n; ++i) roots[i] = i;
std::shuffle(roots.begin(), roots.end(), engine);
if (roots.size() > 500) roots.resize(500);
int result = -1;
for (int root : roots) {
parent.assign(n, -1);
auto bkp_adjlist = adjlist;
result = std::max(result, dfs(root).dp0);
adjlist = std::move(bkp_adjlist);
}
std::cout << result << '\n';
}
