#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ld long double
#define show(x,y) cout << y << " " << #x << endl;
#define show2(x,y,i,j) cout << y << " " << #x << " " << j << " " << #i << endl;
#define show3(x,y,i,j,p,q) cout << y << " " << #x << " " << j << " " << #i << " " << q << " " << #p << endl;
#define show4(x,y) for(auto it:y) cout << it << " "; cout << #x << endl;
typedef pair<int,int>pii;
typedef pair<pii,int>pi2;
mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());
vector<pii>adj[200005];
int dp[200005][3];
void dfs(int index, int par, int len){
int counter=0;
int change=-1e15;
for(auto it:adj[index]){
if(it.first==par) continue;
dfs(it.first,index,it.second);
int hold=max(dp[it.first][0],dp[it.first][2]);
change=max(change,dp[it.first][1]-hold);
counter+=hold;
}
dp[index][0]=counter;
dp[index][2]=counter+change+len;
dp[index][1]=counter+len;
}
int best=0;
void dfs2(int index, int par, int len){
//compute answer
int counter=0;
multiset<pii>se;
for(auto it:adj[index]){
int hold=max(dp[it.first][0],dp[it.first][2]);
int change=dp[it.first][1]-hold;
se.insert({change,it.first});
counter+=hold;
}
//show2(index,index,counter,counter);
best=max(best,counter);
array<int,3>undo={dp[index][0],dp[index][1],dp[index][2]};
se.insert({-1e15,0});
for(auto it:adj[index]){
if(it.first==par) continue;
int hold=max(dp[it.first][0],dp[it.first][2]);
int change=dp[it.first][1]-hold;
se.erase(se.find({change,it.first}));
dp[index][0]=counter-hold;
dp[index][2]=counter-hold+prev(se.end())->first+it.second;
dp[index][1]=counter-hold+it.second;
//cout << index << " " << it.first << " " << dp[index][0] << " " << dp[index][1] << " " << dp[index][2] << "\n";
dfs2(it.first,index,it.second);
dp[index][0]=undo[0];
dp[index][1]=undo[1];
dp[index][2]=undo[2];
se.insert({change,it.first});
}
}
void solve(){
int n;
cin >> n;
int temp,temp2,temp3;
for(int x=0;x<n-1;x++){
cin >> temp >> temp2 >> temp3;
adj[temp].push_back({temp2,temp3});
adj[temp2].push_back({temp,temp3});
}
dfs(1,-1,0);
//reroot
dfs2(1,-1,0);
cout << best;
}
int32_t main(){
ios::sync_with_stdio(0);
cin.tie(0);
//freopen("in.txt","r",stdin);
//freopen("in.txt","w",stdout);
int t=1;
//cin >> t;
while(t--){
solve();
}
}
