#!/bin/python3

import sys

xsame = True
ysame = True

n = int(input().strip())
    
for a0 in range(n):
    x,y = input().strip().split(' ')
    x,y = [int(x),int(y)]
    if a0 == 0:
        allx = x
        ally = y
    if a0 > 0:
        if allx != x:
            xsame = False
        if ally != y:
            ysame = False
        
    
if not xsame and not ysame:
    print('NO')
else:
    print('YES')