#!/usr/bin/env python3

# 28-Z4-1: Půdorys
# Autor: Martin Šerý

def zpracujZaznam():
    pocetBodu = int(input())
    souradnice = list(map(int, input().split()))
    body = list((souradnice[2*i], souradnice[2*i + 1]) for i in range(pocetBodu))

    levaHrana = min(x for (x,y) in body)
    pravaHrana = max(x for (x,y) in body)
    horniHrana = max(y for (x,y) in body)
    spodniHrana = min(y for (x,y) in body)

    for (x, y) in body:
        if not(x == levaHrana or x == pravaHrana or y == horniHrana or y == spodniHrana):
           return "NE"

    return "ANO"


pocetZaznamu=int(input())
for x in range(pocetZaznamu):
    print(zpracujZaznam())