#!/bin/python3

import sys


n = int(input().strip())
p = []
for i in range(n):
    x,y = input().strip().split(' ')
    p.append((int(x),int(y)))
allx = True
ally = True
for i in range(1,n):
    if p[i][0]!=p[0][0]:
        allx = False
    if p[i][1]!=p[0][1]:
        ally = False
        
if allx or ally:
    print("YES")
else:
    print("NO")