//In the name of God
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
const ll maxn = 2e5 + 100;
const ll mod = 1e9 + 7;
const ll inf = 1e18;
#define fast_io ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define file_io freopen("input.txt", "r+", stdin);freopen("output.txt", "w+", stdout);
#define pb push_back
#define Mp make_pair
#define F first
#define S second
#define Sz(x) ll((x).size())
#define all(x) (x).begin(), (x).end()
ll n, dp[maxn][2], pd[maxn][2], par[maxn];
vector<pll> g[maxn];
bool vis[maxn];
void dfs(ll v){
ll mx = -inf;
vis[v] = 1;
for(pll u : g[v]){
if(vis[u.F]) continue;
dfs(u.F);
par[u.F] = u.S;
dp[v][0] += max(dp[u.F][0], dp[u.F][1] + u.S);
mx = max(mx, dp[u.F][0] + u.S - max(dp[u.F][0], dp[u.F][1] + u.S));
}
dp[v][1] = dp[v][0] + mx;
}
void sfd(ll v, ll p = -1){
vis[v] = 1;
ll s = 0;
if(~p) s += max(pd[v][0], pd[v][1] + p);
vector<pll> vec;
if(~p) vec.pb(Mp(pd[v][0] + p - max(pd[v][0], pd[v][1] + p), v));
for(pll u : g[v]){
if(vis[u.F]) continue;
s += max(dp[u.F][0], dp[u.F][1] + u.S);
vec.pb(Mp(dp[u.F][0] + u.S - max(dp[u.F][0], dp[u.F][1] + u.S), u.F));
}
sort(all(vec), greater<pll>());
vec.pb(Mp(-inf, 0));
for(pll u : g[v]){
if(vis[u.F]) continue;
pd[u.F][0] = s - max(dp[u.F][0], dp[u.F][1] + u.S);
pd[u.F][1] = pd[u.F][0] + (vec[0].S == u.F ? vec[1].F : vec[0].F);
sfd(u.F, u.S);
}
return;
}
int main(){
fast_io;
cin >> n;
for(ll i = 1; i < n; i++){
ll v, u, c;
cin >> v >> u >> c;
g[v].pb(Mp(u, c));
g[u].pb(Mp(v, c));
}
dfs(4);
fill(vis, vis + n + 1, 0);
sfd(4);
ll ans = 0;
for(ll i = 1; i <= n; i++){
ans = max(ans, dp[i][0] + max(pd[i][0], pd[i][1] + par[i]));
}
cout << ans;
return 0;
}
