/*#pragma GCC optimize("Ofast,unroll-loops")
#pragma comment(linker, "/stack:200000000")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma,tune=native")*/
/*#pragma GCC optimize("O2")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx,avx2,sse,sse2,fma")*/
#include <bits/stdc++.h>
using namespace std;
using ll=long long int;
using ld=long double;
using pll=pair<ll,ll>;
using pii=pair<int,int>;
using point=complex<double>;
#define F first
#define S second
//#define X real()
//#define Y imag()
#define pb push_back
#define mp make_pair
#define lc v<<1
#define rc v<<1|1
#define fast_io ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);
#define kill(x) cout << x << '\n';exit(0)
#define killshayan kill("done!")
#define killmashtali kill("Hello, World!")
const int N=5e3+10,LN=19,M=3e2+10,SQ=450,BS=737,inf=1e9,NSQ=N/SQ+1;
const ll INF=1e18;
const double pi=acos(-1);
const ld ep=1e-7;
const int MH=1000696969,MD=998244353,MOD=1000000007;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set tree<pii, null_type,greater<pii>, rb_tree_tag,tree_order_statistics_node_update>
ll pow(ll x, ll y, ll mod){
ll ans=1;
while (y != 0) {
if (y & 1) ans = ans * x % mod;
y >>= 1;
x = x * x % mod;
}
return ans;
}
ll n,dp[N][N],a[N],c[N];
vector<ll> adj[N],cp;
void dfs(ll v){
for(ll u : adj[v]) dfs(u);
for(ll i=cp.size()-1; i>=0; i--){
if(i!=a[v]) dp[v][i]=c[v];
for(ll u : adj[v]){
dp[v][i]+=dp[u][i];
}
if(i<cp.size()-1) dp[v][i]=min(dp[v][i],dp[v][i+1]);
}
}
int main(){
fast_io;
cin >> n;
for(ll i=1; i<=n; i++){
ll p;
cin >> p >> a[i] >> c[i];
if(i>1) adj[p].pb(i);
cp.pb(a[i]);
}
sort(cp.begin(),cp.end());
cp.resize(unique(cp.begin(),cp.end())-cp.begin());
for(ll i=1; i<=n; i++) a[i]=lower_bound(cp.begin(),cp.end(),a[i])-cp.begin();
dfs(1);
cout << dp[1][0] << '\n';
return 0;
}
