#include <bits/stdc++.h>
using namespace std;
#define ll long long
const int N = 1005;
const ll inf = 1e18;
ll dp[N][2];
vector<array<ll, 2>> tadj[N], adj[N];
void build(int i, int p) {
adj[i].clear();
for (auto [nxt, w] : tadj[i]) {
if (nxt == p) continue;
build(nxt, i);
adj[i].push_back({nxt, w});
}
}
void root(int i) {
for (auto [nxt, w] : adj[i]) {
root(nxt);
}
for (int carry = 0; carry < 2; carry++) {
ll ans = 0;
if (carry) {
ans = -inf;
}
ll s = 0;
for (auto [nxt, w] : adj[i]) {
s += max(dp[nxt][1] + w, dp[nxt][0]);
}
if (!carry) {
ans = s;
} else {
ll mx = -inf;
for (auto [nxt, w] : adj[i]) {
mx = max(mx, - max(dp[nxt][1] + w, dp[nxt][0]) + dp[nxt][0] + w);
}
ans = s + mx;
}
dp[i][carry] = ans;
}
}
ll ans = 0;
void reroot(int i, array<ll, 3> up) {
array<ll, 2> newdp = {-inf, -inf};
for (int carry = 0; carry < 2; carry++) {
newdp[carry] = 0;
if (carry) {
newdp[carry] = -inf;
}
ll s = 0;
for (auto [nxt, w] : adj[i]) {
s += max(dp[nxt][1] + w, dp[nxt][0]);
}
s += max(up[1] + up[2], up[0]);
if (!carry) {
newdp[carry] = max(newdp[carry], s);
} else {
ll mx = -inf;
for (auto [nxt, w] : adj[i]) {
mx = max(mx, - max(dp[nxt][1] + w, dp[nxt][0]) + dp[nxt][0] + w);
}
mx = max(mx, - max(up[1] + up[2], up[0]) + up[0] + up[2]);
newdp[carry] = max(newdp[carry], s + mx);
}
}
// cout << i << ": " << newdp[0] << '\n';
ans = max(ans, newdp[0]);
int m = adj[i].size();
ll prfmx[m + 1], sufmx[m + 1], prfs[m + 1]{}, sufs[m + 1]{};
prfmx[0] = - max(up[1] + up[2], up[0]) + up[0] + up[2];
sufmx[m] = -inf;
if (max(up[1] + up[2], up[0]) > 0) {
prfs[0] = max(up[1] + up[2], up[0]);
}
for (int j = 0; j < m; j++) {
auto [nxt, w] = adj[i][j];
prfmx[j + 1] = max(prfmx[j], - max(dp[nxt][1] + w, dp[nxt][0]) + dp[nxt][0] + w);
prfs[j + 1] = prfs[j] + max(dp[nxt][1] + w, dp[nxt][0]);
}
for (int j = m - 1; j >= 0; j--) {
auto [nxt, w] = adj[i][j];
sufmx[j] = max(sufmx[j + 1], - max(dp[nxt][1] + w, dp[nxt][0]) + dp[nxt][0] + w);
sufs[j] = sufs[j + 1] + max(dp[nxt][1] + w, dp[nxt][0]);
}
for (int j = 0; j < m; j++) {
auto [nxt, w] = adj[i][j];
ll s = prfs[j] + sufs[j + 1];
ll mx = max(prfmx[j], sufmx[j + 1]);
// cout << j << ' ' << prfmx[j] << ' ' << sufmx[j + 1] << '\n';
reroot(nxt, {s, s + mx, w});
}
}
int main() {
ios_base::sync_with_stdio(0), cin.tie(0);
memset(dp, -1, sizeof dp);
int n;
cin >> n;
for (int i = 1, u, v, w; i < n; i++) {
cin >> u >> v >> w;
tadj[u].push_back({v, w});
tadj[v].push_back({u, w});
}
memset(dp, -1, sizeof dp);
build(1, 0);
root(1);
reroot(1, (array<ll, 3>) {-inf, -inf, -inf});
cout << ans << '\n';
return 0;
}
