#!/bin/python3

import sys

def check(li):
    horiz = True
    verti = True
    horiz_start = None
    verti_start = None
    #print(li)
    for i in li:
        x = i[0]
        y = i[1]
        #print(x,y)
        if not horiz_start:
            horiz_start = x
        elif horiz_start !=x:
            horiz = False
        if not verti_start:
            verti_start = y
        elif verti_start !=y:
            verti = False
        #print(horiz, verti)
        if not horiz and not verti:
            return "NO"
    return "YES"
n = int(input().strip())

li = list()
for a0 in range(n):
    x,y = input().strip().split(' ')
    x,y = [int(x),int(y)]
    li.append((x,y))

print(check(li))