#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
#define all(x) (x).begin(),(x).end()
#define Sort(x) sort(all((x)))
#define X first
#define Y second
#define sep ' '
#define endl '\n'
#define SZ(x) ll(x.size())
ll poww(ll a, ll b, ll md) {
return (!b ? 1 : (b & 1 ? a * poww(a * a % md, b / 2, md) % md : poww(a * a % md, b / 2, md) % md));
}
const ll MAXN = 2e5 + 10;
const ll LOG = 22;
const ll INF = 8e18;
const ll MOD = 2e9 + 7; // 998244353; // 1e9 + 9;
int n , ans , dpDown[MAXN][2];
vector<pii> adj[MAXN];
void DFS(int v , int p = -1){
dpDown[v][0] = dpDown[v][1] = 0;
int mx = -MOD;
for(pii i : adj[v]){
int u = i.X , w = i.Y;
if(u == p) continue;
DFS(u , v);
dpDown[v][0] += max(dpDown[u][0] , dpDown[u][1] + w);
dpDown[v][1] += max(dpDown[u][0] , dpDown[u][1] + w);
mx = max(mx , dpDown[u][0] + w - max(dpDown[u][0] , dpDown[u][1] + w));
}
dpDown[v][1] += mx;
}
int main() {
ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
cin >> n;
if(n > 10000) return 0;
for(int i = 1 ; i < n ; i++){
int v , u , w;
cin >> v >> u >> w;
adj[v].push_back({u , w});
adj[u].push_back({v , w});
}
for(int i = 1 ; i <= n ; i++){
DFS(i);
ans = max(ans , dpDown[i][0]);
}
cout << ans << endl;
return 0;
}
/*
*/
