#include <bits/stdc++.h>
using namespace std;
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n;
cin >> n;
vector<int> a(n), h(n), c(n);
for (int u = 0; u < n; u++) {
cin >> a[u] >> h[u] >> c[u];
a[u]--;
}
vector<map<int, long long>> f(n);
auto add = [](map<int, long long> &x, map<int, long long> &y) {
if (y.size() > x.size()) swap(x, y);
for (auto [h, c] : y) x[h] += c;
};
auto fix = [](map<int, long long> &x, int h, long long c) {
x[h] += c;
auto it = x.lower_bound(h);
while (it != x.begin()) {
it = prev(it);
if (it->second <= c) {
c -= it->second;
it = x.erase(it);
} else {
it->second -= c;
break;
}
}
};
vector<int> deg(n, 0);
queue<int> que;
for (int u = 0; u < n; u++) deg[a[u]]++;
for (int u = 0; u < n; u++) if (!deg[u]) que.push(u);
while (!que.empty()) {
int u = que.front();
que.pop();
fix(f[u], h[u], c[u]);
add(f[a[u]], f[u]);
if (!--deg[a[u]]) que.push(a[u]);
}
long long res = 0;
for (int u = 0; u < n; u++) {
if (deg[u] > 0) {
map<int, long long> sum;
sum[h[u]] += c[u];
deg[u] = 0;
for (int v = a[u]; v != u; v = a[v]) {
add(f[u], f[v]);
sum[h[v]] += c[v];
deg[v] = 0;
}
for (auto [h, c] : sum) {
fix(f[u], h, c);
}
for (auto [h, c] : f[u]) {
res += c;
}
}
}
cout << accumulate(c.begin(), c.end(), 0LL) - res << '\n';
}
