#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    long int i,j,k,q,t,a[10][2],x1,y1,x2,y2;
    cin >> t;
    while(t--){
        cin >> j;
        k = j;
        i = 0;
        x1 = 10001, x2 = -10001, y1 = 10001, y2 = -10001;
        while(k--){
            cin >> a[i][0] >> a[i][1];
            x1 = min(x1,a[i][0]);
            x2 = max(x2,a[i][0]);
            y1 = min(y1,a[i][1]);
            y2 = max(y2,a[i][1]);
            i++;
        }
        
        for(i = 0; i < j; i++){
            q = 0;
            if(a[i][0] == x1 || a[i][0] == x2){
                q = 1;
            }
            if(a[i][1] == y1 || a[i][1] == y2){
                q = 1;
            }
            if(q == 0) break;
        }
        if(q == 1) cout << "YES" << endl;
        else cout << "NO" << endl;
    }
    return 0;
}