#include <bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
#define starburst ios::sync_with_stdio(0), cin.tie(0)
#define pii pair<int,int>
#define F first
#define S second
#define pb push_back
#define all(x) x.begin(),x.end()
#define inf 0x3f3f3f3f
#define N 200005
int n, a, b, c, ans=0;
vector<pii> adj[N];
int in[N], ex[N];
int pw[N];
void dfs(int v, int parent){
int sum=0;//, pw=-inf;
for (int i=0;i<adj[v].size();i++){
int u=adj[v][i].F;
if (u==parent){
pw[v]=adj[v][i].S;
swap(adj[v][i],adj[v].back());
adj[v].pop_back();
i--;
continue;
}
dfs(u,v);
sum+=in[u];
}
in[v]=ex[v]=sum;
for (auto it:adj[v]){
int u=it.F;
if (u==parent) continue;
in[v]=max(in[v], sum-in[u]+ex[u]+pw[v]+it.S);
}
}
void dfs2(int v, int parent, int to){
int sum=parent;
int mx=to-parent+pw[v];
int mxx=-inf;
for (auto it:adj[v]){
int u=it.F;
if (u==parent) continue;
sum+=in[u];
int now=ex[u]-in[u]+it.S;
if (mx<now){
mxx=mx;
mx=now;
}
else if (mxx<now) mxx=now;
}
ans=max(ans, sum);
for (auto it:adj[v]){
int u=it.F;
if (u==parent) continue;
int now=mx;
if (now==ex[u]-in[u]+it.S) now=mxx;
dfs2(u, max(sum-in[u], now+sum-in[u]+it.S), sum-in[u]);
}
}
signed main(){
starburst;
cin >> n;
for (int i=0;i<n-1;i++){
cin >> a >> b >> c;
adj[a].pb({b,c});
adj[b].pb({a,c});
}
// for (int v=1;v<=n;v++){
//// memset(x,0,sizeof(in));
//// memset(y,0,sizeof(ex));
// for (int i=1;i<=n;i++) in[i]=ex[i]=0;
// dfs(v,0);
// //dfs(v);
// ans=max(ans, in[v]);
// }
pw[1]=-inf;
dfs(1,0);
dfs2(1,0,0);
cout << ans;
return 0;
}
