/*input
2
3
0 0
0 1
1 0
4
0 0
0 2
2 0
1 1
*/
#include <bits/stdc++.h>
#include<stdio.h>
using namespace std;
#define F(i,a,b) for(int i = a; i <= b; i++)
#define RF(i,a,b) for(int i = a; i >= b; i--)
#define pii pair<int,int>
#define PI 3.14159265358979323846264338327950288
#define ll long long
#define ff first
#define ss second
#define pb(x) push_back(x)
#define mp(x,y) make_pair(x,y)
#define debug(x) cout << #x << " = " << x << endl
#define INF 1000000009
#define mod 1000000007
#define S(x) scanf("%d",&x)
#define S2(x,y) scanf("%d%d",&x,&y)
#define P(x) printf("%d\n",x)
#define all(v) v.begin(),v.end()
#define MX 200005
int BIT[200005];
void update(int id,int val) {
	for(int i=id;i<=MX;i+=i&-i) BIT[i]+=val;
}
int query(int id) {
	int sum=0;
	for(int i=id;i>0;i-=i&-i) sum+=BIT[i];
	return sum;
}
set <ll> setx,sety;
pii arr[20];
int main() 
{
	std::ios::sync_with_stdio(false);
	ll t;
	cin>>t;
	while(t--)
	{
		setx.clear();
		sety.clear();
		ll n;
		cin>>n;
		ll minx,miny,maxx,maxy;
		minx = miny = 1000000;
		maxx = maxy = -1000000;
		F(i,1,n)
		{
			ll x,y;
			cin>>x>>y;
			arr[i] = {x,y};
			minx = min(minx,x);
			maxx = max(maxx,x);
			miny = min(miny,y);
			maxy = max(maxy,y);
			setx.insert(x);
			sety.insert(y);
		}
		bool flag = 0;
		F(i,1,n)
		{
			ll x = arr[i].ff;
			ll y = arr[i].ss;
			if(x == minx || x==maxx || y==miny || y==maxy)
				continue;
			else
				flag = 1;
		}
		//ll a = setx.size();
		//ll b = sety.size();
		if(!flag)
			cout<<"YES";
		else 
			cout<<"NO";
		cout<<endl;
	}
	return 0;
}