#!/bin/python3

import sys

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