#!/bin/python3

import sys

xpoints=[]
ypoints=[]
n = int(input().strip())
for a0 in range(n):
    x,y = input().strip().split(' ')
    x,y = [int(x),int(y)]
    xpoints.append(x)
    ypoints.append(y)
xlen=len(set(xpoints))
ylen=len(set(ypoints))
if xlen==1 or ylen==1:
    print("YES")
else:
    print("NO")