#include <bits/stdc++.h>

using namespace std;

struct treap {
    int key;
    int prior;
    int ind;
    treap *l;
    treap *r;
    treap *par;

    treap(int kkey, int kprior, int kind) {
        key = kkey;
        prior = kprior;
        ind = kind;
        l = r = par = nullptr;
    }
};

const int N = 5e4 + 20;
vector< int > pt[N];
vector< int > lt[N];
vector< int > rt[N];
treap *t;
treap *p;

void Insert(treap *cur) {
    if (!t) {
        p = cur;
        t = p;
    } else if (p->prior < cur->prior) {
        p->r = cur;
        p->r->par = p;
        p = p->r;
    } else {
        while (p->prior > cur->prior)
            if (p->par)
                p = p->par;
            else
                break;
        if (!p->par) {
            cur->l = p;
            p->par = cur;
            p = cur;
        } else {
            cur->l = p->r;
            p->r = cur;
            cur->par = p;
            p = cur;
        }
    }
}

int get_ind(treap *cur) {
    if (cur)
        return cur->ind;
    else
        return 0;
}

void print(treap *cur) {
    cout << cur->ind << "\n";
    if (!cur)
        return;
    print(cur->l);
    pt[cur->ind].push_back(get_ind(cur->par));
    lt[cur->ind].push_back(get_ind(cur->l));
    rt[cur->ind].push_back(get_ind(cur->r));
    print(cur->r);
}

int main() {
//    freopen("input.txt", "r", stdin);
//    freopen("output.txt", "w", stdout);
    int n;
    cin >> n;
    vector< pair< int, pair< int, int > > > v;
    for (int i = 1; i <= n; i++) {
        int x;
        int y;
        cin >> x >> y;
        v.push_back({x, {y, i}});
    }
    sort(v.begin(), v.end());
    for (int i = 0; i < v.size(); i++) {
        int x = v[i].first;
        int y = v[i].second.first;
        int index = v[i].second.second;
        treap *cur = new treap(x, y, index);
        Insert(cur);
    }
    cout << "YES\n" << t->ind;
    print(t);
    for (int i = 1; i <= n; i++)
        cout << pt[i][0] << " " << lt[i][0] << " " << rt[i][0] << "\n";
    return 0;
}