#!/bin/python3

import sys

n = int(input().strip())
points = []
for a0 in range(n):
    x,y = input().strip().split(' ')
    x,y = [int(x),int(y)]
    points.append([x,y])

xs = [i[0] for i in points]
ys = [i[1] for i in points]

if len(list(set(xs))) == 1 or len(list(set(ys))) == 1: print("YES")
else: print("NO")