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

int dieFirstSad(vector < vector < int > > &arr, int i)
{
    if (i < 0)
    {
        return 0;
    }

    int maxx = max(dieFirstSad(arr, arr[i][0]),dieFirstSad(arr, arr[i][1]));
    return maxx + 1;
}

int main() {
    ifstream fin("height.in");
    ofstream fout("height.out");

    int n;
    fin >> n; //how many lines
    if (n == 0)
    {
        fout << 0;
        return 0;
    }
    vector < vector < int > > arr;

    arr.resize(n);

    int left, right;
    for(int i = 0; i < n; i++)
    {
        int tmp;
        fin >>tmp>> left >> right;
        arr[i].push_back(left-1);
        arr[i].push_back(right-1);
    }

    fout << dieFirstSad(arr, 0);

    return 0;
}