#include <bits/stdc++.h>
#define f first
#define s second
#define m_p make_pair
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define vec vector
#define pb push_back
#define sz(x) (int)(x).size()
#define pw(x) (1LL<<(x))
#define fast_resp ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef long double ld;
template<class T> bool umin(T &a,const T &b){return (a>b?a=b,1:0);}
template<class T> bool umax(T &a,const T &b){return (a<b?a=b,1:0);}
const int N=5e3+1;
const ll inf=1e18;
vec<int> g[N];
ll dp[N][N];
int c[N],a[N],h[N];
void dfs(int v){
// for(int i=0;i<N;i++){
// dp[v][i]=(h[v]==i?0:c[v]);
// }
// cout<<"DFS "<<v<<endl;
for(auto &z : g[v]){
dfs(z);
for(int j=0;j<N;j++)
dp[v][j]+=dp[z][j];
// for(int j=1;j<N;j++){
// if(umin(dp[v][j],dp[v][j-1]))
// cerr<<"V "<<v<<' '<<j<<endl;
// }
}
for(int j=N-1;j>=0;j--){
dp[v][j]=min(dp[v][j]+(j==h[v]?0:c[v]),(j+1<N?dp[v][j+1]:inf));
}
// for(int j=0;j<N;j++){
// cerr<<"DE "<<dp[v][j]<<' '<<v<<' '<<j<<endl;
// }
}
signed main(){
fast_resp;
int n;
cin>>n;
vec<int>kek;
for(int i=0;i<n;i++){
cin>>a[i]>>h[i]>>c[i];--a[i];
if(a[i]!=i) g[a[i]].pb(i);
kek.pb(h[i]);
}
sort(all(kek));kek.erase(unique(all(kek)),kek.end());
for(int i=0;i<n;i++) h[i]=lower_bound(all(kek),h[i])-kek.begin();
dfs(0);
cout<<dp[0][0];
return 0;
}
/*
*/
