#include <bits/stdc++.h>
using namespace std;
const int MAX_N = 5000;
const long long INF = 1e15;
int n;
int parent[MAX_N + 1], height[MAX_N + 1], cost[MAX_N + 1];
long long dp[MAX_N + 1][MAX_N + 1];
vector<int> children[MAX_N + 1];
map<int, int> mp;
void dfs( int u ) {
for ( int v: children[u] )
dfs( v );
dp[u][n] = INF;
// printf( "%d\n", u );
for ( int x = n - 1; x >= 0; x-- ) {
dp[u][x] = (height[u] == x ? 0 : cost[u]);
for ( int v: children[u] )
dp[u][x] += dp[v][x];
dp[u][x] = min( dp[u][x], dp[u][x + 1] );
// printf( "%d ", dp[u][x] );
}
//printf( "\n" );
}
int main() {
cin >> n;
for ( int v = 1; v <= n; v++ )
cin >> parent[v] >> height[v] >> cost[v];
for ( int v = 2; v <= n; v++ )
children[parent[v]].push_back( v );
for ( int v = 1; v <= n; v++ )
mp[height[v]] = 1;
int val = 0;
for ( auto p: mp )
mp[p.first] = val++;
for ( int v = 1; v <= n; v++ )
height[v] = mp[height[v]];
dfs( 1 );
cout << dp[1][0] << "\n";
return 0;
}
