#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][2];
void dfs(int v,int p,int pw){
if ((int) adj[v].size() == 1){
dp[v][1][0] = dp[v][1][1] = dp[v][0][1] = -2*inf;
dp[v][0][0] = 0;
return;
}
vector<int> ve;
int s = 0;
for (auto [u,w] : adj[v]){
if (u == p) continue;
dfs(u,v,w);
int val = max({dp[u][0][0],dp[u][0][1],dp[u][1][0],dp[u][1][1]});
s += val;
ve.pb(max(dp[u][1][0],dp[u][0][0])-val+w);
}
sort(all(ve));
int sz = ve.size();
dp[v][0][0] = s;
dp[v][0][1] = -2*inf;
dp[v][1][1] = s+ve.back()+pw;
if (sz > 1) dp[v][1][0] = s+ve[sz-1]+ve[sz-2];
else dp[v][1][0] = -2*inf;
}
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;
}
int r = -1;
rep(i,1,n+1) if ((int) adj[i].size() > 1){
r = i;
break;
}
dfs(r,0,-2*inf);
cout << max(dp[r][1][0],dp[r][0][0]);
}
