#include <iostream>
#include <vector>

using namespace std;

struct Node {
    int value;
    int left;
    int right;
};

Node Arr[200001];
int minimum = -1e9 - 1;
int maximum = 1e9 + 1;

bool check(int strNum, int maximum, int minimum)
{
    if(Arr[strNum].value > maximum || Arr[strNum].value < minimum) return false;
    if(Arr[strNum].left != 0 && !(check(Arr[strNum].left, Arr[strNum].value - 1, minimum)))
    {
        return false;
    }
    if(Arr[strNum].right != 0 && !(check(Arr[strNum].right, maximum, Arr[strNum].value + 1)))
    {
        return false;
    }
    return true;
}

int main()
{
    freopen("check.in", "r", stdin);
    freopen("check.out", "w", stdout);
    int n;
    cin >> n;
    if(!n)
    {
        cout << "YES";
        return 0;
    }
    int key1, key2, key3;
    for(int i = 1; i < n + 1; i++) {
        cin >> key1;
        Arr[i].value = key1;
        cin >> key2;
        Arr[i].left = key2;
        cin >> key3;
        Arr[i].right = key3;
    }
    if(check(1, maximum, minimum)) cout << "YES";
    else cout << "NO";
}