#!/bin/python3

import sys

xarr = []
yarr = []


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

var1 = True
for x in xarr:
    if x != xarr[0]:
        var1 = False

var2 = True
for y in yarr:
    if y != yarr[0]:
        var2 = False
        

if not var1 and not var2:
    print("NO")
else:
    print("YES")