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

#define rep(i,a,b) for (int i = a; i < b; i++)
#define trav(a,b) for (auto a : b)
#define all(x) begin(x),end(x)
#define lld long long 

void Solve() {
	int n;
	cin>>n;
	vector<pair<lld,pair<lld,lld> > >V;
	rep(i,0,n){
		lld x,y;
		cin>>x>>y;
		V.push_back({x+y,{x,y}});
	}
	sort(V.begin(),V.end());
	reverse(V.begin(),V.end());
	lld last=3e9+1;
	lld tot=0;
	vector<int> T;
	trav(a,V){
		//cout<<a.first<<" "<<last<<endl;
		while(last>a.first && tot>0){
			if(tot%2==1){
				T.push_back(last);
			}
			tot/=2;
			last--;
		}
		last=a.first;
		tot++;
		//cout<<last<<" U"<<tot<<endl;
	}
	while(last>=-10 && tot>0){
		if(tot%2==1){
			T.push_back(last);
		}
		tot/=2;
		last--;
	}
	trav(a,T){
		if(a<-1){
			cout<<"NO\n";
			return;
		}
	}
	int ans=0;
	trav(a,T){
		if(a==-1)ans+=2;
		if(a==0)ans++;
	}
	if(ans>=3){
		cout<<"NO\n";
		return;
	}
	cout<<"YES\n";
}


signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	int tt = 1;
	cin >> tt;
	while (tt--) Solve();
	return 0;
}