#include <bits/stdc++.h>
using namespace std;
template <class T>
inline bool mnto(T& a, T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T& a, T b) {return a < b ? a = b, 1: 0;}
#define REP(i, s, e) for (int i = s; i < e; i++)
#define RREP(i, s, e) for (int i = s; i >= e; i--)
typedef long long ll;
typedef long double ld;
#define MP make_pair
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
#define MT make_tuple
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define pb emplace_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
#define INF 1000000005
#define LINF 1000000000000000005
#define MOD 1000000007
#define MAXN 5005
int n;
int h[MAXN], c[MAXN];
vi adj[MAXN];
ll memo[MAXN][MAXN];
ll dp(int u, int ptake, int p) {
if (memo[u][ptake] != -1) return memo[u][ptake];
int pv = -1;
if (ptake != -1) {
pv = h[ptake];
}
vector<ll> notake, take;
for (int v : adj[u]) {
notake.pb(dp(v, u, u));
take.pb(dp(v, ptake, u));
}
ll notakev = 0, takev = c[u];
REP (i, 0, notake.size()) {
notakev += notake[i];
takev += take[i];
}
//printf("%d: %lld %lld\n", u, notakev, takev);
if (pv > h[u]) {
return memo[u][ptake] = takev;
}
return memo[u][ptake] = min(takev, notakev);
}
int main() {
scanf("%d", &n);
REP (i, 1, n + 1) {
int a; scanf("%d%d%d", &a, &h[i], &c[i]);
if (i != 1) adj[a].pb(i);
}
memset(memo, -1, sizeof memo);
printf("%lld\n", dp(1, -1, -1));
return 0;
}
