#include<bits/stdc++.h>
using namespace std;
#define int long long
#define tiii tuple<int,int,int>
int INF = numeric_limits<int>::max()/2;
struct SegmentTree{
vector<int> S;
int len = 1;
SegmentTree(int n){
while(len < n) len <<= 1;
S.resize(2*len, INF);
}
int query(int ql, int qr, int l = 0, int r = -1, int i = 1){
if(r == -1) r = len;
if(ql <= l && r <= qr) return S[i];
if(r <= ql || qr <= l) return INF;
int mid = (l+r)/2;
return min(query(ql,qr,l,mid,i*2),query(ql,qr,mid,r,i*2+1));
}
void upd(int i, int v){
i += len;
S[i] = v;
for(i /= 2; i > 0; i/=2){
S[i] = min(S[i*2], S[i*2+1]);
}
}
};
vector<int> arr;
vector<int> par;
vector<int> cost;
vector<SegmentTree> dp;
vector<vector<int>> adj;
int n;
void DFS(int v){
for(auto u : adj[v]){
DFS(u);
}
for(int k = 0; k < n; k++){
int add = 0;
if(k != arr[v]){
add = cost[v];
}
int c = 0;
for(auto u : adj[v]){
c += dp[u].query(k, n+1);
}
dp[v].upd(k,add + c);
}
}
int32_t main(){
cin >> n;
cost = arr = par = vector<int>(n);
dp.resize(n, SegmentTree(n));
adj.resize(n);
for(int i = 0; i < n; i++){
int a,h,c;
cin >> a >> h >> c;
a--;
par[i] = a;
arr[i] = h;
cost[i] = c;
}
vector<int> sorted = arr;
sort(sorted.begin(),sorted.end());
map<int,int> toInd;
for(int i = 0; i < n; i++){
toInd[sorted[i]] = i;
}
for(int i = 0; i < n; i++){
arr[i] = toInd[arr[i]];
}
for(int i = 1; i < n; i++){
adj[par[i]].push_back(i);
}
DFS(0);
cout << dp[0].query(0, n+1) << endl;
}
