#include <bits/stdc++.h>
#pragma GCC target("sse,sse2,avx2")
#pragma GCC optimize("unroll-loops,O2")
#define rep(i,l,r) for (int i = l; i < r; i++)
#define repr(i,r,l) for (int i = r; i >= l; i--)
#define X first
#define Y second
#define all(x) (x).begin() , (x).end()
#define pb push_back
#define endl '\n'
#define debug(x) cerr << #x << " : " << x << endl;
using namespace std;
typedef long long ll;
typedef pair<int,int> pll;
constexpr int N = 2e5+10,mod = 1e9+7,maxm = 210;
constexpr ll inf = 1e9+10;
inline int mkay(int a,int b){
if (a+b >= mod) return a+b-mod;
// if (a+b < 0) return a+b+mod;
return a+b;
}
inline int poww(int a,int k){
if (k < 0) return 0;
int z = 1;
while (k){
if (k&1) z = 1ll*z*a%mod;
a = 1ll*a*a%mod;
k >>= 1;
}
return z;
}
vector<pll> adj[N];
int dp[N][2];
int h[N];
void pre(int v,int p){
for (auto [u,w] : adj[v]){
if (u != p){
h[u] = h[v]+w;
pre(u,v);
}
}
}
void dfs(int v,int p){
if ((int) adj[v].size() == 1 && p != 0){
dp[v][1] = -2*inf;
dp[v][0] = 0;
return;
}
// vector<int> ve;
int s = 0,mx = -2*inf;
for (auto [u,w] : adj[v]){
if (u == p) continue;
dfs(u,v);
int val = max(dp[u][0],dp[u][1]+w);
s += val;
mx = max(mx,dp[u][0]-val+w);
// ve.pb(dp[u][0]-val+w);
}
// sort(all(ve));
dp[v][0] = s;
dp[v][1] = s + mx;
}
int main(){
ios :: sync_with_stdio(0); cin.tie(0);
int n;
cin >> n;
rep(i,1,n){
int u,v,w;
cin >> u >> v >> w;
adj[u].pb({v,w});
adj[v].pb({u,w});
}
if (n <= 2){
cout << 0 << endl;
return 0;
}
pre(1,0);
int vert = 1,mx = 0;
rep(i,1,n+1){
if (h[i] > mx){
mx = h[i];
vert = i;
}
}
int ans = 0;
dfs(vert,0);
ans = max(ans,dp[vert][0]);
/* rep(i,1,n+1){
if ((int)adj[i].size() > 1) continue;
dfs(i,0);
ans = max(ans,dp[i][0]);
}*/
cout << ans;
}
