#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp> // Common file
// #include <ext/pb_ds/tree_policy.hpp> // Including tree_order_statistics_node_update
using namespace std;
// using namespace __gnu_pbds;
#define fileIO(name) if(fopen(name".inp", "r")) {freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout);}
#define SPEED ios_base :: sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define EL cout << '\n'
#define dbg(x) cout << #x << " = " << (x) << ' '
#define dbgp(x) cout << #x << " = (" << (x.fi) << ", " << (x.se) << ") "
#define dbga(x, l, r) {cout << #x << '[' << l << ", " << r << "] = { "; for(int i = l; i <= (int)r; ++i) cout << x[i] << ' '; cout << "} ";}
#define epl emplace
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define mp make_pair
#define sqr(x) ((x) * (x))
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define lwb lower_bound
#define upb upper_bound
#define ctz __builtin_ctzll // or __builtin_ctz
#define pct __builtin_popcountll // or __builtin_popcount
typedef long long ll;
typedef long double ldb;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef pair<ll, ll> pll;
typedef pair<ll, int> pli;
typedef pair<int, ll> pil;
typedef pair<int, int> pii;
typedef pair<ldb, ldb> pld;
typedef pair<double, double> pdd;
template<class T1, class T2> bool minimize(T1 &a, T2 b){return a > b ? a = b, true : false;}
template<class T1, class T2> bool maximize(T1 &a, T2 b){return a < b ? a = b, true : false;}
// int d4x[4] = {1, 0, -1, 0}, d8x[8] = {0, 1, 1, 1, 0, -1, -1, -1};
// int d4y[4] = {0, 1, 0, -1}, d8y[8] = {1, 1, 0, -1, -1, -1, 0, 1};
// typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
// typedef tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_multiset;
const int N = 2e5 + 3;
const ll oo = 1e18;
int n;
ll dp[N][2], f[N][2], res = -oo;
vector<pil> adj[N];
void dfs1(int u, int par){
for(int i = 0; i < adj[u].size(); ++i){
int v = adj[u][i].fi;
if(v == par) continue;
dfs1(v, u);
ll w = adj[u][i].se;
dp[u][0] += max(dp[v][0], dp[v][1] + w);
}
for(int i = 0; i < adj[u].size(); ++i){
int v = adj[u][i].fi;
if(v == par) continue;
ll w = adj[u][i].se;
maximize(dp[u][1], dp[u][0] - max(dp[v][0], dp[v][1] + w) + dp[v][0] + w);
}
if(u == 1) res = dp[u][0];
}
void dfs2(int u, int par, ll w_u_par){
pii best = {-1, -1};
int sz = adj[u].size(), num_child = 0;
vector<ll> contrib(sz), a(sz);
if(u != 1) maximize(res, dp[u][0] + max(f[u][0], f[u][1] + w_u_par));
ll contrib_par = max(f[u][1] + w_u_par, f[u][0]);
for(int i = 0; i < sz; ++i){
int v = adj[u][i].fi;
if(v == par) continue;
ll w = adj[u][i].se;
++num_child;
contrib[i] = max(dp[v][0], dp[v][1] + w);
a[i] = -contrib[i] + w + dp[v][0];
f[v][0] = contrib_par + dp[u][0] - contrib[i];
if(u != 1) f[v][1] = f[u][0] + w_u_par + dp[u][0] - contrib[i];
//neu chon cha cua u de noi tiep, neu u = 1 thi ko co cha nen ko the lam theo cach nay
if(best.fi == -1 || a[best.fi] < a[i]){
best.se = best.fi;
best.fi = i;
}
else if(best.se == -1 || a[best.se] < a[i]){
best.se = i;
}
}
//neu chon mot con khac v cua u de noi tiep
if(num_child > 1) for(int i = 0; i < sz; ++i){
int v = adj[u][i].fi;
ll add_val = (i == best.fi ? a[best.se] : a[best.fi]);
maximize(f[v][1], contrib_par + dp[u][0] - contrib[i] + add_val);
}
contrib.clear(); a.clear();
for(int i = 0; i < sz; ++i){
int v = adj[u][i].fi;
if(v == par) continue;
dfs2(v, u, adj[u][i].se);
}
}
void TS_2392(){
cin >> n;
for(int i = 1; i < n; ++i){
int u, v; ll w;
cin >> u >> v >> w;
adj[u].eb(v, w); adj[v].eb(u, w);
}
for(int i = 1; i <= n; ++i){
f[i][1] = dp[i][1] = -oo;
}
dfs1(1, 0); dfs2(1, 0, -oo);
cout << res;
}
int main(){
SPEED; fileIO("text1");
int num_test = 1; //cin >> num_test;
for(int itest = 1; itest <= num_test; ++itest){
TS_2392();
}
return 0;
}
