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

struct pt {
    int x, y;
    pt() { }
    pt(int x, int y) : x(x), y(y) { }
};

int n, q;
pt pts[10];

int main() {
    cin >> q;
    
    while (q--){
        cin >> n;
        int xl = 1<<30, xh = -(1<<30), yl = 1<<30, yh = -(1<<30);
        for (int i = 0; i < n; i++){
            cin >> pts[i].x >> pts[i].y;
            xl = min(xl, pts[i].x);
            yl = min(yl, pts[i].y);
            xh = max(xh, pts[i].x);
            yh = max(yh, pts[i].y);
        }
        int i;
        for (i = 0; i < n; i++)
            if (pts[i].x != xl && pts[i].x != xh && pts[i].y != yl && pts[i].y != yh)
                break;
        cout << (i == n ? "YES" : "NO") << endl;
    }
}