#!/bin/python3

import sys

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