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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    
    int t;
    cin>>t;
    while(t--)
        {
         int n,f,xmi,xma,ymi,yma,p,q;
         cin>>n;
        cin>>p>>q;
        xmi=xma=p;
        ymi=yma=q;
        vector<int>x(n);
        vector<int>y(n);
        x[0]=p;
        y[0]=q;    
        for(int i=1;i<n;i++)
            {
           
                    cin>>p>>q;
                    x[i]=p;
                    y[i]=q; 
                    xmi=min(xmi,p);
                    xma=max(xma,p);
                    ymi=min(ymi,q);
                    yma=max(yma,q);
            }
        f=1;
        for(int i=0;i<n;i++)
            {
             f=1;
               if(x[i]==xmi || x[i]==xma)
                   if(y[i]>=ymi && y[i]<=yma)
                       f=0;
               if(y[i]==ymi || y[i]==yma)
                   if(x[i]>=xmi && x[i]<=xma)
                       f=0;                 
               if(f)
                   break;
            }
              
            
        if(f)
            cout<<"NO"<<endl;
        else
            cout<<"YES"<<endl;
    }
    
    return 0;
}