def foo(l):
    if len(l) != 4:
        return "YES"
    xcor = []
    ycor = []
    x = {}
    y = {}
    for i in l:
        xcor.append(i[0])
        ycor.append(i[1])

        
    max_x = max(xcor)
    max_y = max(ycor)
    
    return "NO"
    
 

test_c = int(input())

for i in range(test_c):
    a = int(input())
    temp = []
    
    for i in range(a):
        b = input()
        
        temp.append(b.split())
    print(foo(temp))