#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;


int main() {

    freopen("check.in", "r", stdin);
    freopen("check.out", "w", stdout);

    int n;
    cin >> n;
    vector <int> key(n);
    vector <int> left(n);
    vector <int> right(n);
    for (int i = 0; i < n; i++) {
        cin >> key[i] >> left[i] >> right[i];
        left[i] = max(0, left[i] - 1);
        right[i] = max(0, right[i] - 1);
    }
    for (int i = 0; i < n; i++) {
        if (left[i] != 0) {
            if (key[i] < key[left[i]]) {
                cout << "NO";
                return 0;
            }
        }
        if (right[i] != 0) {
            if (key[i] > key[right[i]]) {
                cout << "NO";
                return 0;
            }
        }
    }
    cout << "YES";

}