#!/bin/python3

import sys

def allEqualX(listX):
    for elem in listX:
        if elem != listX[0]:
            return False
    return True

def allEqualY(listY):
    for elem in listY:
        if elem != listY[0]:
            return False
    return True

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

if allEqualX(listX) or allEqualY(listY):
    print('YES')
else:
    print('NO')