#include <fstream>

using namespace std;

int main() {
    ifstream fin("height.in");
    ofstream fout("height.out");
    int N;
    int Left_element;
    int Right_element;
    int key;
    int max;
    int i;
    fin >> N;
    if (N < 1) {fout << N;} else {
        int *array = new int[N+1];
        array[1] = 1;
        for (i = 1; i <= N; i++) {
            fin >> key >> Left_element >> R;
            if (Left_element > 0) {array[Left_element] = array[i]+1;};
            if (Right_element > 0) {array[Right_element] = array[i]+1;};
        };
        max = array[N];
        for (int i = 1; i < N; i++) {
            if (max < array[i]) {max=array[i];};
        };
        fout << max;
    }
    return 0;
}