#!/bin/python3

import sys


n = int(input().strip())

xpointsall = []
ypointsall =[]
for a0 in range(n):
    x,y = input().strip().split(' ')
    x,y = [int(x),int(y)]
    xpointsall.append(x)
    ypointsall.append(y)
flag = None
if(all(x == xpointsall[0] for x in xpointsall)):
    flag = "YES"
else:
    if(all(y == ypointsall[0] for y in ypointsall)):
        flag = "YES"
    else:
        flag = "NO"
print(flag)