#include <bits/stdc++.h>
using namespace std;
void just_do_it();
int main() {
#ifdef KAMIRULEZ
freopen("kamirulez.inp", "r", stdin);
freopen("kamirulez.out", "w", stdout);
#endif
ios_base::sync_with_stdio(0);
cin.tie(0);
just_do_it();
return 0;
}
const int maxN = 2e5 + 20;
vector<pair<int, int>> adj[maxN];
int par_w[maxN];
int dp[maxN][2];
int tot[maxN];
multiset<int> gain[maxN];
int res;
void dfs1(int u, int p) {
tot[u] = 0;
gain[u].clear();
for (auto x: adj[u]) {
int v = x.first;
int w = x.second;
if (v != p) {
par_w[v] = w;
dfs1(v, u);
tot[u] += max(dp[v][0], dp[v][1]);
gain[u].insert(w + dp[v][0] - max(dp[v][0], dp[v][1]));
}
}
dp[u][0] = tot[u];
dp[u][1] = tot[u] + (!gain[u].empty() ? *gain[u].rbegin() + par_w[u] : 0);
}
void dfs2(int u, int p) {
res = max(res, dp[u][0]);
for (auto x: adj[u]) {
int v = x.first;
int w = x.second;
if (v != p) {
par_w[u] = w;
par_w[v] = 0;
tot[u] -= max(dp[v][0], dp[v][1]);
gain[u].erase(gain[u].find(w + dp[v][0] - max(dp[v][0], dp[v][1])));
dp[u][0] = tot[u];
dp[u][1] = tot[u] + (!gain[u].empty() ? *gain[u].rbegin() + par_w[u] : 0);
tot[v] += max(dp[u][0], dp[u][1]);
gain[v].insert(w + dp[u][0] - max(dp[u][0], dp[u][1]));
dp[v][0] = tot[v];
dp[v][1] = tot[v] + (!gain[v].empty() ? *gain[v].rbegin() + par_w[v] : 0);
dfs2(v, u);
par_w[u] = 0;
par_w[v] = w;
gain[v].erase(gain[v].find(w + dp[u][0] - max(dp[u][0], dp[u][1])));
tot[v] -= max(dp[u][0], dp[u][1]);
dp[v][0] = tot[v];
dp[v][1] = tot[v] + (!gain[v].empty() ? *gain[v].rbegin() + par_w[v] : 0);
tot[u] += max(dp[v][0], dp[v][1]);
gain[u].insert(w + dp[v][0] - max(dp[v][0], dp[v][1]));
dp[u][0] = tot[u];
dp[u][1] = tot[u] + (!gain[u].empty() ? *gain[u].rbegin() + par_w[u] : 0);
}
}
}
void just_do_it() {
int n;
cin >> n;
for (int i = 0; i < n - 1; i++) {
int u, v, w;
cin >> u >> v >> w;
adj[u].emplace_back(v, w);
adj[v].emplace_back(u, w);
}
dfs1(1, -1);
dfs2(1, -1);
cout << res;
}
