#!/bin/python3

import sys


n = int(input().strip())
all_points = []
for a0 in range(n):
    x,y = input().strip().split(' ')
    x,y = [int(x),int(y)]
    all_points.append((x,y))
    
x_cord = [tp[0] for tp in all_points]
y_cord = [tp[1] for tp in all_points]
if len(set(x_cord))==1 or len(set(y_cord))==1:
    print('YES')
else:
    print('NO')