#include <bits/stdc++.h>

using namespace std;

int main() {
  cin.tie(0)->sync_with_stdio(0);
  for (int tc = (cin >> tc, tc); tc--; ) {
    int n; cin >> n;
    set<array<int, 3>> bya, byb, ava;
    for (int i = 0; i < 3 * n; ++i) {
      int a, b; cin >> a >> b;
      bya.insert({a, b, i});
      byb.insert({b, a, i});
    }
    vector<array<int, 3>> ans;
    while (byb.size()) {
      int ub = byb.begin()->front();
      while (bya.size() && bya.begin()->front() <= ub) {
        auto [a, b, i] = *bya.begin();
        ava.insert({b, a, i});
        bya.erase(bya.begin());
      }
      if (ava.size() < 3) break;
      ans.push_back({});
      for (int j = 0; j < 3; ++j) {
        auto [b, a, i] = *ava.begin();
        ava.erase(ava.begin());
        byb.erase({b, a, i});
        ans.back()[j] = i + 1;
      }
    }
    if (byb.size()) { cout << "No\n"; continue; }
    cout << "Yes\n";
    for (auto& x: ans) for (auto x: x) cout << x << ' ';
    cout << '\n';
  }
}