#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int , int> pii;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int maxn = 1e4 + 10;
const ll mod = 1e9+7;
#define pb push_back
#define endl '\n'
#define dokme(x) cout << x , exit(0)
#define ms(x , y) memset(x , y , sizeof x)
ll pw(ll a, ll b, ll md = mod){ll res = 1;while(b){if(b&1){res=(a*res)%md;}a=(a*a)%md;b>>=1;}return(res);}
int n;
int dp[maxn][2] , ans;
vector < pii > adj[maxn];
void dfs(int v , int par = 0){
for(auto [u , w] : adj[v])if(u ^ par)
dfs(u , v),
dp[v][0] += max(dp[u][0] , dp[u][1] + w);
dp[v][1] = -2e9 - 10;
for(auto [u , w] : adj[v])if(u ^ par)
dp[v][1] = max(dp[v][1] , dp[v][0] + w + dp[u][0] - max(dp[u][0] , dp[u][1] + w));
}
void solve(int v , int par = 0){
ans = max(ans , dp[v][0]);
int mx[2] = {int(-2e9 - 10) , int(-2e9 - 10)};
for(auto [u , w] : adj[v]){
mx[1] = max(mx[1] , dp[u][0] + w - max(dp[u][1] + w , dp[u][0]));
if(mx[0] < mx[1])swap(mx[0] , mx[1]);
}
for(auto [u , w] : adj[v])if(u ^ par){
int a = dp[u][1] , b = dp[u][0] , c = dp[v][0] , d = dp[v][1];
bool imx = w + dp[u][0] - max(dp[u][0] , dp[u][1] + w) == mx[0];
dp[v][1] -= max(dp[u][0] , dp[u][1] + w);
if(imx)dp[v][1] += mx[1] - mx[0];
dp[v][0] -= max(dp[u][0] , dp[u][1] + w);
dp[u][1] += max(dp[v][0] , dp[v][1] + w);
dp[u][1] = max(dp[u][1] , dp[u][0] + w + dp[v][0]);
dp[u][0] += max(dp[v][0] , dp[v][1] + w);
solve(u , v);
dp[u][1] = a , dp[u][0] = b , dp[v][0] = c , dp[v][1] = d;
}
}
int32_t main(){
ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
cin >> n;
for(int i = 1 ; i < n ; i ++){
int a , b , c;
cin >> a >> b >> c;
adj[a].pb({b , c});
adj[b].pb({a , c});
}
dfs(1);
solve(1);
cout << ans;
return(0);
}
