#include <bits/stdc++.h>
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;
typedef long double ld;

#define pb push_back
#define ff first
#define ss second

void solve(){
	ll t;
	cin>>t;
	while(t--){
		ll n;cin>>n;
		map<ll,ll> mapi, mp;
		for(int ii=0;ii<n;ii++){
			ll i,j;
			cin>>i>>j;
			mapi[-i-j]++;
			ll k = -i-j;
			while(mapi[k] > 1){
				mapi[k+1]++;
				mapi[k]-=2;
				k++;
			}
		}
		ll ss = 0;
		for(auto[pw, cnt] : mapi){
			if(pw < 0 && cnt > 0)
				ss++;
		}
		if(mapi[1] && mapi[0] && ss == 0)
			cout << "NO\n";
		else if(mapi[1] && mapi[0])
			cout << "NO\n";
		else
			cout << "YES\n";
		
		
		
	}
}

int main(){
	cin.tie(0);
	ios_base::sync_with_stdio(0);
	cout<<fixed<<setprecision(12);
	
	solve();
	
}