#include <bits/stdc++.h>
#define pb push_back
#define int int64_t
#define pii pair<int, int>
#define X first
#define Y second
#define all(x) (x).begin(),(x).end()
#define lb lower_bound
#define ub upper_bound

using namespace std;

const int inf = 1e18;

void p(auto A){
	for(auto e : A)cout << e << ' ';
	cout << '\n';
}

struct fenwick{
	vector<int>A;
	fenwick(int n){
		A.assign(n+5, 0);
	}
	void upd(int k, int v){
		k++;
		for(;k<A.size(); k+=k&-k)A[k]+=v;
	}
	int qer(int k){
		k++;
		int ret = 0;
		for(;k>0;k-=k&-k)ret+=A[k];
		return ret;
	}
};

struct segtree{
	vector<pii>A;
	segtree(int n){
		A.assign(4*n, {0, 0});
	}
	
	pii conq(pii a, pii b){
		if(a.X < b.X)return a;
		else return b;
	}
	
	void upd(int v, int tl, int tr, int pos, int val){
		if(tl > pos || tr < pos)return;
		if(tl == pos && tr == pos){
			A[v] = {val, pos};
			return;
		}
		int tm = (tl+tr)/2;
		upd(v*2, tl, tm, pos, val);
		upd(v*2+1, tm+1, tr, pos, val);
		A[v] = conq(A[v*2], A[v*2+1]);
	}
	pii qer(int v, int tl, int tr, int l, int r){
		if(tl > r || tr < l)return{inf, -1};
		if(tl >= l && tr <= r)return A[v];
		int tm = (tl+tr)/2;
		pii a1 = qer(v*2, tl, tm, l, r);
		pii a2 = qer(v*2+1, tm+1, tr, l, r);
		return conq(a1, a2);
	}
};

void solve(){
	int n; cin >> n;
	vector<int>A(n+1);
	fenwick ft(n);
	vector<pii>ins(n);
	for(int i = 0; i< n; i++)cin >> ins[i].X >> ins[i].Y;
	reverse(all(ins));
	
	set<int>S;
	for(int i = 1; i<= n; i++)S.insert(i);
	
	for(auto[x,y]:ins){
		int id = x + ft.qer(x);
		A[*S.lb(id)] = y;
		S.erase(S.lb(id));
		ft.upd(x, 1);
	}
		
	/*
	for(auto[x, y] : ins){
		A[x+ft.qer(x)] = y;
		ft.upd(x, 1);
	}
	
	set<int>S;
	for(int i = 1; i<= n; i++)S.insert(i);
	for(auto[x,y]:ins){
		A[*S.lb(x)]=y;
		S.erase(S.lb(x));
	}*/
	
	segtree seg(n+1);
	for(int i = 1; i<= n; i++)seg.upd(1, 0, n, i, A[i]);
	vector<pii> ans;
	
	//cerr << "YES" << endl;
	
	auto rec = [&](auto&& self, int l, int r, int id)->void{
		if(r < l)return;
		pii cur = seg.qer(1, 0, n, l, r);
		ans.pb({id, cur.X});
		self(self, l, cur.Y-1, id);
		self(self, cur.Y+1, r, cur.Y+1);
	};
	rec(rec, 1, n, 1);
	for(auto[x, y] : ans)cout << x << ' ' << y << '\n';
}

	

signed main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	int t = 1;
	cin >> t;
	while(t--)solve();
}


//freopen(".in", "r", stdin);
//freopen(".out", "w", stdout);