#if __INCLUDE_LEVEL__ == 0

#include __BASE_FILE__

void Solve() {
  int n;
  IN(n);
  vector<int> a(3 * n), b(3 * n);
  for (int i : Rep(0, 3 * n)) {
    IN(a[i], b[i]);
  }

  vector<int> order(ALL(Rep(0, 3 * n)));
  ranges::sort(order, {}, LAMBDA(i, pair(a[i], b[i])));

  priority_queue q(greater{}, vector<pair<int, int>>{});
  vector<array<int, 3>> ans;
  ans.reserve(n);
  for (int i : order) {
    auto Check = [&]() -> bool {
      if (Sz(q) < 2) {
        return false;
      }
      return a[i] <= q.top().first;
    };
    if (Check()) {
      int x = q.top().second;
      q.pop();
      int y = q.top().second;
      q.pop();
      ans.push_back({x + 1, y + 1, i + 1});
    } else {
      q.emplace(b[i], i);
    }
  }
  if (Sz(q)) {
    OUT("No");
    return;
  }

  assert(Sz(ans) == n);
  OUT("Yes");
  ranges::for_each(ans, LIFT(OUT));
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);

  int t;
  IN(t);
  while (t--) {
    Solve();
  }
}

#elif __INCLUDE_LEVEL__ == 1

#include <bits/stdc++.h>

template <class T> concept Range = std::ranges::range<T> && !std::convertible_to<T, std::string_view>;
template <class T> concept Tuple = std::__is_tuple_like<T>::value && !Range<T>;

namespace std {

istream& operator>>(istream& is, Range auto&& r) {
  for (auto&& e : r) is >> e;
  return is;
}
istream& operator>>(istream& is, Tuple auto&& t) {
  apply([&](auto&... xs) { (is >> ... >> xs); }, t);
  return is;
}

ostream& operator<<(ostream& os, Range auto&& r) {
  auto sep = "";
  for (auto&& e : r) os << exchange(sep, " ") << e;
  return os;
}
ostream& operator<<(ostream& os, Tuple auto&& t) {
  auto sep = "";
  apply([&](auto&... xs) { ((os << exchange(sep, " ") << xs), ...); }, t);
  return os;
}

}  // namespace std

using namespace std;

#define LAMBDA(x, ...) ([&](auto&& x) -> decltype(auto) { return __VA_ARGS__; })
#define LIFT(f) ([&](auto&&... xs) -> decltype(auto) { return f(forward<decltype(xs)>(xs)...); })
#define ALL(r) begin(r), end(r)
#define Rep(...) [](int l, int r) { return views::iota(min(l, r), r); }(__VA_ARGS__)
#define Sz(r) int(size(r))
#define IN(...) (cin >> forward_as_tuple(__VA_ARGS__))
#define OUT(...) (cout << forward_as_tuple(__VA_ARGS__) << '\n')

#endif  // __INCLUDE_LEVEL__ == 1