#include <bits/extc++.h>
using namespace __gnu_pbds;
using namespace std;

#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;

template<class T>
using Tree = tree<T, null_type, less<T>, rb_tree_tag,
    tree_order_statistics_node_update>;

void solve() {
	int n; cin >> n;
	vector<int> p(n);
	Tree<int> pos;
	for (int i = 0; i < n; i++) {
		pos.insert(i);
	}

	vector<pair<int, int>> inp(n);
	for (int i = 0; i < n; i++) {
		cin >> inp[i].first >> inp[i].second;
		inp[i].first--;
	}
	reverse(inp.begin(), inp.end());

	for (auto [pp, h]: inp) {
		int ps = *pos.find_by_order(pp);
		pos.erase(pos.find_by_order(pp));
		p[ps] = h;

		//cout << ps << '\n';
	}

	//for (int i: p) cout << i << ' ';
	//cout << '\n';

	vector<int> dp;
	vector<vector<int>> lis;
	for (int i = n-1; i >= 0; i--) {
		auto it = upper_bound(dp.begin(), dp.end(), p[i]);
		int id = it - dp.begin();
		if (it == dp.end()) {
			dp.push_back(p[i]);
			lis.push_back(vector<int>(0));
		}
		dp[id] = p[i];
		lis[id].push_back(p[i]);
	}

	/*
	for (auto v: lis) {
		for (int i: v) cout << i << ' ';
		cout << '\n';
	}
	*/

	int cursz = 0;
	while (lis[0].size()) {
		int sz = cursz + 1;
		for (int i = 0; i < lis.size(); i++) {
			if (lis[i].empty()) break;
			cout << sz << ' ' << lis[i].back() << '\n';
			lis[i].pop_back();
			cursz++;
		}
	}
}

signed main() {
	ios::sync_with_stdio(0); cin.tie(0);
	
	int t; cin >> t;
	while (t--) {
		solve();
	}
	
	return 0;
}