#include <cstring>
#include <iostream>
#include <vector>
using namespace std;

const int MAXN = 1e5 + 5;

vector<int> tree[MAXN];
int amount[MAXN];
int mem[MAXN][2];
int N, Rt;

int dfs(int node, int flag) {
  if (mem[node][flag] > -1) {
    return mem[node][flag];
  }

  mem[node][0] = 0;
  mem[node][1] = amount[node];

  for (int i = 0; i < tree[node].size(); i++) {
    int leaf = tree[node][i];
    mem[node][0] += max(dfs(leaf, 0), dfs(leaf, 1));
    mem[node][1] += dfs(leaf, 0);
  }

  return mem[node][flag];
}

int main() {
  // Init
  cin >> N;
  memset(mem, -1, sizeof mem);
  for (int i = 0; i < N; i++) {
    int depends, idx, c;
    cin >> depends >> idx >> c;
    amount[idx] = c;
    if (depends == 0) {
      Rt = idx;
    } else {
      tree[depends].push_back(idx);
    }
  }
  // Calculating!
  printf("%d", max(dfs(Rt, 1), dfs(Rt, 0)));
}