#include <iostream>
#include <vector>
const int MAXN = 2e5 + 10;
struct Edge
{
int to, cost;
Edge(){};
Edge(int to, int cost)
{
this->to = to;
this->cost = cost;
}
};
int n;
std::vector < Edge > adj[MAXN];
int dp[MAXN][2];
int up[MAXN];
void read()
{
std::cin >> n;
for(int i = 1; i < n; i++)
{
int u, v, cost;
std::cin >> u >> v >> cost;
adj[u].push_back(Edge(v, cost));
adj[v].push_back(Edge(u, cost));
}
}
void dfs(int u, int par)
{
dp[u][0] = dp[u][1] = 0;
for(Edge &e : adj[u])
{
int v = e.to;
int cost = e.cost;
if(v == par)
continue;
up[v] = cost;
dfs(v, u);
int curmax = dp[v][0];
if(curmax < dp[v][1])
curmax = dp[v][1];
dp[u][0] += curmax;
}
for(Edge &e : adj[u])
{
int v = e.to;
int cost = e.cost;
if(v == par)
continue;
int curmax = dp[v][0];
if(curmax < dp[v][1])
curmax = dp[v][1];
int cur = dp[u][0] - curmax + dp[v][0] + cost + up[u];
if(cur > dp[u][1])
dp[u][1] = cur;
}
}
void solve()
{
int ans = 0;
for(int i = 1; i <= n; i++)
{
dfs(i, i);
if(ans < dp[i][0])
ans = dp[i][0];
}
std::cout << ans << '\n';
}
int main()
{
std::ios_base::sync_with_stdio(false);
std::cin.tie(nullptr);
std::cout.tie(nullptr);
read();
solve();
return 0;
}
