#include <bits/stdc++.h>
using namespace std;
const int64_t inf = 1e15;
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
// dp[i][j] = min cost to change subtree rooted at i, when the elem at i >= h[j]
int n;
cin >> n;
vector<vector<int>> adj(n + 1);
vector<int> h(n + 1), c(n + 1);
vector<pair<int, int>> sort_h(n);
for (int i = 1, a; i <= n; ++i) {
cin >> a >> h[i] >> c[i];
if (a != i) {
adj[a].push_back(i);
}
sort_h[i - 1] = {h[i], i};
}
sort(sort_h.begin(), sort_h.end());
vector<int> nodes;
auto dfs = [&](auto &&self, int u) -> void {
for (int &i : adj[u]) {
self(self, i);
}
nodes.push_back(u);
};
dfs(dfs, 1);
vector dp(n + 1, vector<int64_t>(n + 1, inf));
vector dp_suff(n + 1, vector<int64_t>(n));
for (int &i : nodes) {
for (int j = 1; j <= n; ++j) {
dp[i][j] = c[i] * (i != j); // cost to change our value
// either we dont change root, so all children get a value >= ours
for (int &ch : adj[i]) {
pair<int, int> p = {h[j], -1};
auto it = lower_bound(sort_h.begin(), sort_h.end(), p);
int64_t best = dp_suff[ch][it - sort_h.begin()];
dp[i][j] += best;
}
}
for (int j = n - 1; j >= 0; --j) {
dp_suff[i][j] = dp[i][sort_h[j].second];
if (j != n - 1) {
dp_suff[i][j] = min(dp_suff[i][j], dp_suff[i][j + 1]);
}
}
}
cout << *min_element(dp[1].begin(), dp[1].end()) << '\n';
}
