// [node][0] is current node is *ordinary*
// [node][1] is current node is *connector*
// connector: node between two blue wires
// condition for connector:
// atleast one child node is ordinary
#include <bits/stdc++.h>
using namespace std;
#define int ll
//#define endl '\n'
#define fast_io ios::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define pb push_back
#define re resize
#define ff first
#define ss second
#define all(x) (x).begin(), (x).end()
#define loop(i, n) for(int i = 0; i < n; i++)
#define loop1(i, n) for(int i = 1; i <= n; i++)
#define print(x) cout << #x << ": " << x << endl
typedef long long ll;
typedef vector<int> vi;
typedef array<int, 2> ii;
typedef array<int, 3> ti;
typedef vector<ii> vii;
typedef vector<ti> vti;
typedef priority_queue<int> pq;
template<class T> bool ckmin(T&a, T b) { bool B = a > b; a = min(a, b); return B; }
template<class T> bool ckmax(T&a, T b) { bool B = a < b; a = max(a, b); return B; }
const int inf = 1e17;
const int maxn = 2e5 + 5;
int n;
vii adj[maxn];
ii sub[maxn];
ii min_diff[maxn];
ii min_diff2[maxn];
void calc_dfs(int u, int p) {
for(auto [v, w] : adj[u]) if(v != p)
calc_dfs(v, u);
sub[u][0] = 0;
sub[u][1] = 0;
min_diff[u] = {inf, -1};
for(auto [v, w] : adj[u]) if(v != p) {
sub[u][0] += max(sub[v][0], sub[v][1] + w);
sub[u][1] += max(sub[v][0], sub[v][1] + w);
ii min_d = {max(sub[v][0], sub[v][1] + w) - (sub[v][0] + w), v};
if(min_d <= min_diff[u]) {
min_diff2[u] = min_diff[u];
min_diff[u] = min_d;
} else if(min_d < min_diff2[u]) {
min_diff2[u] = min_d;
}
}
sub[u][1] -= min_diff[u][0];
}
void move(int u, int v, int w) {
ii sub_u = sub[u];
ii sub_v = sub[v];
sub[u][0] -= max(sub_v[0], sub_v[1] + w);
sub[u][1] -= max(sub_v[0], sub_v[1] + w);
if(min_diff[u][1] == v) {
sub[u][1] += min_diff[u][0];
sub[u][1] -= min_diff2[u][0];
}
sub[v][0] += max(sub[u][0], sub[u][1] + w);
sub[v][1] += max(sub[u][0], sub[u][1] + w);
if(min_diff[v][1] == u) sub[v][1] += min_diff2[v][0];
else sub[v][1] += min_diff[v][0];
ii min_d = {max(sub[u][0], sub[u][1] + w) - (sub[u][0] + w), u};
if(min_d <= min_diff[v]) {
min_diff2[v] = min_diff[v];
min_diff[v] = min_d;
} else if(min_d < min_diff2[v]) {
min_diff2[v] = min_d;
}
sub[v][1] -= min_diff[v][0];
}
int dfs(int u, int p) {
int res = sub[u][0];
for(auto [v, w] : adj[u]) if(v != p) {
move(u, v, w);
ckmax(res, dfs(v, u));
move(v, u, w);
}
return res;
}
void solve() {
cin >> n;
loop(i, n-1) {
int u, v, w; cin >> u >> v >> w;
adj[u].pb({v, w});
adj[v].pb({u, w});
}
calc_dfs(1, 1);
cout << dfs(1, 1) << endl;
}
signed main() {
fast_io;
int t = 1; //cin >> t;
while(t--)
solve();
//cout << flush;
return 0;
}
