#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
int t,n,x[1001],y[1001],ans,sum,i,amin=-99999,amax=99999,bmin=-99999,bmax=99999;
bool k=false;
int main() {
   cin>>t;
   while(t--)
       {
       amin=99999;amax=-99999;bmin=99999;bmax=-99999;
       k=false;
       cin>>n;
      for(i=1;i<=n;i++)
          {
          cin>>x[i]>>y[i];
     
     
            amin=min(amin,x[i]);
      bmin=min(bmin,y[i]);
      amax=max(amax,x[i]);
      bmax=max(bmax,y[i]);
          }
        
      for(i=1;i<=n;i++)
          {
      if(y[i]!=bmax && y[i]!=bmin && x[i]!=amin && x[i]!=amax && k==false){cout<<"NO"<<endl;k=true;}  
      }
        
       if(k==false)
           cout<<"YES"<<endl;
   }
    return 0;
}